diff --git a/app/src/main/java/org/dslul/openboard/inputmethod/compat/ClipboardManagerCompat.java b/app/src/main/java/org/dslul/openboard/inputmethod/compat/ClipboardManagerCompat.java
index 1665c5343..33546a67b 100644
--- a/app/src/main/java/org/dslul/openboard/inputmethod/compat/ClipboardManagerCompat.java
+++ b/app/src/main/java/org/dslul/openboard/inputmethod/compat/ClipboardManagerCompat.java
@@ -2,14 +2,12 @@
 
 package org.dslul.openboard.inputmethod.compat;
 
-import android.annotation.TargetApi;
 import android.content.ClipData;
 import android.content.ClipboardManager;
 import android.os.Build;
 
 public class ClipboardManagerCompat {
 
-    @TargetApi(Build.VERSION_CODES.P)
     public static void clearPrimaryClip(ClipboardManager cm) {
         if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.P) {
             try {
@@ -23,7 +21,6 @@ public class ClipboardManagerCompat {
         }
     }
 
-    @TargetApi(Build.VERSION_CODES.O)
     public static Long getClipTimestamp(ClipData cd) {
         if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.O) {
             return cd.getDescription().getTimestamp();
diff --git a/app/src/main/java/org/dslul/openboard/inputmethod/compat/CompatUtils.kt b/app/src/main/java/org/dslul/openboard/inputmethod/compat/CompatUtils.kt
deleted file mode 100644
index 302ad734e..000000000
--- a/app/src/main/java/org/dslul/openboard/inputmethod/compat/CompatUtils.kt
+++ /dev/null
@@ -1,190 +0,0 @@
-/*
- * Copyright (C) 2011 The Android Open Source Project
- * modified
- * SPDX-License-Identifier: Apache-2.0 AND GPL-3.0-only
- */
-
-package org.dslul.openboard.inputmethod.compat
-
-import android.text.TextUtils
-import org.dslul.openboard.inputmethod.latin.utils.Log
-import java.lang.reflect.Constructor
-import java.lang.reflect.Field
-import java.lang.reflect.InvocationTargetException
-import java.lang.reflect.Method
-
-object CompatUtils {
-    private val TAG = CompatUtils::class.java.simpleName
-    fun getClass(className: String?): Class<*>? {
-        return try {
-            Class.forName(className!!)
-        } catch (e: ClassNotFoundException) {
-            null
-        }
-    }
-
-    fun getMethod(targetClass: Class<*>?, name: String?,
-                  vararg parameterTypes: Class<*>?): Method? {
-        if (targetClass == null || TextUtils.isEmpty(name)) {
-            return null
-        }
-        try {
-            return targetClass.getMethod(name!!, *parameterTypes)
-        } catch (_: SecurityException) { // ignore
-        } catch (_: NoSuchMethodException) {
-        }
-        return null
-    }
-
-    fun getField(targetClass: Class<*>?, name: String?): Field? {
-        if (targetClass == null || TextUtils.isEmpty(name)) {
-            return null
-        }
-        try {
-            return targetClass.getField(name!!)
-        } catch (_: SecurityException) { // ignore
-        } catch (_: NoSuchFieldException) {
-        }
-        return null
-    }
-
-    fun getConstructor(targetClass: Class<*>?,
-                       vararg types: Class<*>?): Constructor<*>? {
-        if (targetClass == null || types == null) {
-            return null
-        }
-        try {
-            return targetClass.getConstructor(*types)
-        } catch (_: SecurityException) { // ignore
-        } catch (_: NoSuchMethodException) {
-        }
-        return null
-    }
-
-    fun newInstance(constructor: Constructor<*>?, vararg args: Any?): Any? {
-        if (constructor == null) {
-            return null
-        }
-        try {
-            return constructor.newInstance(*args)
-        } catch (e: InstantiationException) {
-            Log.e(TAG, "Exception in newInstance", e)
-        } catch (e: IllegalAccessException) {
-            Log.e(TAG, "Exception in newInstance", e)
-        } catch (e: IllegalArgumentException) {
-            Log.e(TAG, "Exception in newInstance", e)
-        } catch (e: InvocationTargetException) {
-            Log.e(TAG, "Exception in newInstance", e)
-        }
-        return null
-    }
-
-    operator fun invoke(receiver: Any?, defaultValue: Any?,
-                        method: Method?, vararg args: Any?): Any? {
-        if (method == null) {
-            return defaultValue
-        }
-        try {
-            return method.invoke(receiver, *args)
-        } catch (e: IllegalAccessException) {
-            Log.e(TAG, "Exception in invoke", e)
-        } catch (e: IllegalArgumentException) {
-            Log.e(TAG, "Exception in invoke", e)
-        } catch (e: InvocationTargetException) {
-            Log.e(TAG, "Exception in invoke", e)
-        }
-        return defaultValue
-    }
-
-    fun getFieldValue(receiver: Any?, defaultValue: Any?,
-                      field: Field?): Any? {
-        if (field == null) {
-            return defaultValue
-        }
-        try {
-            return field[receiver]
-        } catch (e: IllegalAccessException) {
-            Log.e(TAG, "Exception in getFieldValue", e)
-        } catch (e: IllegalArgumentException) {
-            Log.e(TAG, "Exception in getFieldValue", e)
-        }
-        return defaultValue
-    }
-
-    fun setFieldValue(receiver: Any?, field: Field?, value: Any?) {
-        if (field == null) {
-            return
-        }
-        try {
-            field[receiver] = value
-        } catch (e: IllegalAccessException) {
-            Log.e(TAG, "Exception in setFieldValue", e)
-        } catch (e: IllegalArgumentException) {
-            Log.e(TAG, "Exception in setFieldValue", e)
-        }
-    }
-
-    fun getClassWrapper(className: String?): ClassWrapper {
-        return ClassWrapper(getClass(className))
-    }
-
-    class ClassWrapper(private val mClass: Class<*>?) {
-        fun exists(): Boolean {
-            return mClass != null
-        }
-
-        fun <T> getMethod(name: String?,
-                          defaultValue: T, vararg parameterTypes: Class<*>?): ToObjectMethodWrapper<T> {
-            return ToObjectMethodWrapper(getMethod(mClass, name, *parameterTypes),
-                    defaultValue)
-        }
-
-        fun getPrimitiveMethod(name: String?, defaultValue: Int,
-                               vararg parameterTypes: Class<*>?): ToIntMethodWrapper {
-            return ToIntMethodWrapper(getMethod(mClass, name, *parameterTypes),
-                    defaultValue)
-        }
-
-        fun getPrimitiveMethod(name: String?, defaultValue: Float,
-                               vararg parameterTypes: Class<*>?): ToFloatMethodWrapper {
-            return ToFloatMethodWrapper(getMethod(mClass, name, *parameterTypes),
-                    defaultValue)
-        }
-
-        fun getPrimitiveMethod(name: String?,
-                               defaultValue: Boolean, vararg parameterTypes: Class<*>?): ToBooleanMethodWrapper {
-            return ToBooleanMethodWrapper(getMethod(mClass, name, *parameterTypes),
-                    defaultValue)
-        }
-
-    }
-
-    @Suppress("unchecked_cast")
-    class ToObjectMethodWrapper<T>(private val mMethod: Method?, private val mDefaultValue: T) {
-        operator fun invoke(receiver: Any?, vararg args: Any?): T {
-            return CompatUtils.invoke(receiver, mDefaultValue, mMethod, *args) as T
-        }
-
-    }
-
-    class ToIntMethodWrapper(private val mMethod: Method?, private val mDefaultValue: Int) {
-        operator fun invoke(receiver: Any?, vararg args: Any?): Int {
-            return CompatUtils.invoke(receiver, mDefaultValue, mMethod, *args) as Int
-        }
-
-    }
-
-    class ToFloatMethodWrapper(private val mMethod: Method?, private val mDefaultValue: Float) {
-        operator fun invoke(receiver: Any?, vararg args: Any?): Float {
-            return CompatUtils.invoke(receiver, mDefaultValue, mMethod, *args) as Float
-        }
-
-    }
-
-    class ToBooleanMethodWrapper(private val mMethod: Method?, private val mDefaultValue: Boolean) {
-        operator fun invoke(receiver: Any?, vararg args: Any?): Boolean {
-            return CompatUtils.invoke(receiver, mDefaultValue, mMethod, *args) as Boolean
-        }
-
-    }
-}
\ No newline at end of file
diff --git a/app/src/main/java/org/dslul/openboard/inputmethod/compat/CursorAnchorInfoCompatWrapper.kt b/app/src/main/java/org/dslul/openboard/inputmethod/compat/CursorAnchorInfoCompatWrapper.kt
deleted file mode 100644
index 9b7482e66..000000000
--- a/app/src/main/java/org/dslul/openboard/inputmethod/compat/CursorAnchorInfoCompatWrapper.kt
+++ /dev/null
@@ -1,164 +0,0 @@
-/*
- * Copyright (C) 2014 The Android Open Source Project
- * modified
- * SPDX-License-Identifier: Apache-2.0 AND GPL-3.0-only
- */
-
-package org.dslul.openboard.inputmethod.compat
-
-import android.annotation.TargetApi
-import android.graphics.Matrix
-import android.graphics.RectF
-import android.os.Build
-import android.os.Build.VERSION_CODES
-import android.view.inputmethod.CursorAnchorInfo
-
-/**
- * A wrapper for [CursorAnchorInfo], which has been introduced in API Level 21. You can use
- * this wrapper to avoid direct dependency on newly introduced types.
- */
-open class CursorAnchorInfoCompatWrapper internal constructor() {
-    open val selectionStart: Int
-        get() {
-            throw UnsupportedOperationException("not supported.")
-        }
-
-    open val selectionEnd: Int
-        get() {
-            throw UnsupportedOperationException("not supported.")
-        }
-
-    open val composingText: CharSequence?
-        get() {
-            throw UnsupportedOperationException("not supported.")
-        }
-
-    open val composingTextStart: Int
-        get() {
-            throw UnsupportedOperationException("not supported.")
-        }
-
-    open val matrix: Matrix?
-        get() {
-            throw UnsupportedOperationException("not supported.")
-        }
-
-    open fun getCharacterBounds(index: Int): RectF? {
-        throw UnsupportedOperationException("not supported.")
-    }
-
-    open fun getCharacterBoundsFlags(index: Int): Int {
-        throw UnsupportedOperationException("not supported.")
-    }
-
-    open val insertionMarkerBaseline: Float
-        get() {
-            throw UnsupportedOperationException("not supported.")
-        }
-
-    open val insertionMarkerBottom: Float
-        get() {
-            throw UnsupportedOperationException("not supported.")
-        }
-
-    open val insertionMarkerHorizontal: Float
-        get() {
-            throw UnsupportedOperationException("not supported.")
-        }
-
-    open val insertionMarkerTop: Float
-        get() {
-            throw UnsupportedOperationException("not supported.")
-        }
-
-    open val insertionMarkerFlags: Int
-        get() {
-            throw UnsupportedOperationException("not supported.")
-        }
-
-    @TargetApi(VERSION_CODES.LOLLIPOP)
-    private class RealWrapper(private val mInstance: CursorAnchorInfo) : CursorAnchorInfoCompatWrapper() {
-
-        override val selectionStart: Int
-        get() {
-            return mInstance.selectionStart
-        }
-
-        override val selectionEnd: Int
-        get() {
-            return mInstance.selectionEnd
-        }
-
-        override val composingText: CharSequence?
-        get() {
-            return mInstance.composingText
-        }
-
-        override val composingTextStart: Int
-        get() {
-            return mInstance.composingTextStart
-        }
-
-        override val matrix: Matrix?
-        get() {
-            return mInstance.matrix
-        }
-
-        override fun getCharacterBounds(index: Int): RectF? {
-            return mInstance.getCharacterBounds(index)
-        }
-
-        override fun getCharacterBoundsFlags(index: Int): Int {
-            return mInstance.getCharacterBoundsFlags(index)
-        }
-
-        override val insertionMarkerBaseline: Float
-        get() {
-            return mInstance.insertionMarkerBaseline
-        }
-
-        override val insertionMarkerBottom: Float
-        get() {
-            return mInstance.insertionMarkerBottom
-        }
-
-        override val insertionMarkerHorizontal: Float
-        get() {
-            return mInstance.insertionMarkerHorizontal
-        }
-
-        override val insertionMarkerTop: Float
-        get() {
-            return mInstance.insertionMarkerTop
-        }
-
-        override val insertionMarkerFlags: Int
-        get() {
-            return mInstance.insertionMarkerFlags
-        }
-
-    }
-
-    companion object {
-        /**
-         * The insertion marker or character bounds have at least one visible region.
-         */
-        const val FLAG_HAS_VISIBLE_REGION = 0x01
-        /**
-         * The insertion marker or character bounds have at least one invisible (clipped) region.
-         */
-        const val FLAG_HAS_INVISIBLE_REGION = 0x02
-        /**
-         * The insertion marker or character bounds is placed at right-to-left (RTL) character.
-         */
-        const val FLAG_IS_RTL = 0x04
-
-        @JvmStatic
-        @TargetApi(VERSION_CODES.LOLLIPOP)
-        fun wrap(instance: CursorAnchorInfo?): CursorAnchorInfoCompatWrapper? {
-            return if (Build.VERSION.SDK_INT < VERSION_CODES.LOLLIPOP) {
-                null
-            } else instance?.let { RealWrapper(it) }
-        }
-    }
-}
\ No newline at end of file
diff --git a/app/src/main/java/org/dslul/openboard/inputmethod/compat/InputMethodSubtypeCompatUtils.kt b/app/src/main/java/org/dslul/openboard/inputmethod/compat/InputMethodSubtypeCompatUtils.kt
index 58ce0fcc3..5251409ec 100644
--- a/app/src/main/java/org/dslul/openboard/inputmethod/compat/InputMethodSubtypeCompatUtils.kt
+++ b/app/src/main/java/org/dslul/openboard/inputmethod/compat/InputMethodSubtypeCompatUtils.kt
@@ -14,18 +14,13 @@ import org.dslul.openboard.inputmethod.latin.utils.locale
 import java.util.*
 
 object InputMethodSubtypeCompatUtils {
-    // Note that InputMethodSubtype.getLanguageTag() is expected to be available in Android N+.
-    private val GET_LANGUAGE_TAG = CompatUtils.getMethod(InputMethodSubtype::class.java, "getLanguageTag")
-
     @JvmStatic
     fun getLocaleObject(subtype: InputMethodSubtype): Locale { // Locale.forLanguageTag() is available only in Android L and later.
-        if (Build.VERSION.SDK_INT >= VERSION_CODES.LOLLIPOP) {
-            val languageTag = CompatUtils.invoke(subtype, null, GET_LANGUAGE_TAG) as String?
-            if (!languageTag.isNullOrEmpty()) {
+        if (Build.VERSION.SDK_INT >= VERSION_CODES.N) {
+            val languageTag = subtype.languageTag
+            if (languageTag.isNotEmpty())
                 return Locale.forLanguageTag(languageTag)
-            }
         }
         return LocaleUtils.constructLocaleFromString(subtype.locale())
     }
-
 }
\ No newline at end of file
diff --git a/app/src/main/java/org/dslul/openboard/inputmethod/compat/SuggestionSpanUtils.kt b/app/src/main/java/org/dslul/openboard/inputmethod/compat/SuggestionSpanUtils.kt
index d3b682d96..611fe187e 100644
--- a/app/src/main/java/org/dslul/openboard/inputmethod/compat/SuggestionSpanUtils.kt
+++ b/app/src/main/java/org/dslul/openboard/inputmethod/compat/SuggestionSpanUtils.kt
@@ -14,6 +14,7 @@ import android.text.style.SuggestionSpan
 import org.dslul.openboard.inputmethod.annotations.UsedForTesting
 import java.util.*
 
+// todo: this is not compat any more
 object SuggestionSpanUtils {
     @JvmStatic
     @UsedForTesting
diff --git a/app/src/main/java/org/dslul/openboard/inputmethod/compat/TextInfoCompatUtils.kt b/app/src/main/java/org/dslul/openboard/inputmethod/compat/TextInfoCompatUtils.kt
deleted file mode 100644
index ad944505e..000000000
--- a/app/src/main/java/org/dslul/openboard/inputmethod/compat/TextInfoCompatUtils.kt
+++ /dev/null
@@ -1,47 +0,0 @@
-/*
- * Copyright (C) 2014 The Android Open Source Project
- * modified
- * SPDX-License-Identifier: Apache-2.0 AND GPL-3.0-only
- */
-
-package org.dslul.openboard.inputmethod.compat
-
-import android.os.Build
-import android.view.textservice.TextInfo
-import org.dslul.openboard.inputmethod.annotations.UsedForTesting
-
-object TextInfoCompatUtils {
-    // Note that TextInfo.getCharSequence() is supposed to be available in API level 21 and later.
-    private val TEXT_INFO_GET_CHAR_SEQUENCE = CompatUtils.getMethod(TextInfo::class.java, "getCharSequence")
-
-    @get:UsedForTesting
-    val isCharSequenceSupported: Boolean
-        get() = TEXT_INFO_GET_CHAR_SEQUENCE != null
-
-    @JvmStatic
-    @UsedForTesting
-    fun newInstance(charSequence: CharSequence, start: Int, end: Int, cookie: Int,
-                    sequenceNumber: Int): TextInfo {
-        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.LOLLIPOP)
-            return TextInfo(charSequence, start, end, cookie, sequenceNumber)
-        return TextInfo(charSequence.subSequence(start, end).toString(), cookie, sequenceNumber)
-    }
-
-    /**
-     * Returns the result of [TextInfo.getCharSequence] when available. Otherwise returns
-     * the result of [TextInfo.getText] as fall back.
-     * @param textInfo the instance for which [TextInfo.getCharSequence] or
-     * [TextInfo.getText] is called.
-     * @return the result of [TextInfo.getCharSequence] when available. Otherwise returns
-     * the result of [TextInfo.getText] as fall back. If `textInfo` is `null`,
-     * returns `null`.
-     */
-    @JvmStatic
-    @UsedForTesting
-    fun getCharSequenceOrString(textInfo: TextInfo): CharSequence {
-        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.LOLLIPOP)
-            return textInfo.charSequence
-        val defaultValue = textInfo.text
-        return CompatUtils.invoke(textInfo, defaultValue, TEXT_INFO_GET_CHAR_SEQUENCE) as CharSequence
-    }
-}
\ No newline at end of file
diff --git a/app/src/main/java/org/dslul/openboard/inputmethod/compat/ViewOutlineProviderCompatUtils.kt b/app/src/main/java/org/dslul/openboard/inputmethod/compat/ViewOutlineProviderCompatUtils.kt
index 6185a0f2e..54700ed27 100644
--- a/app/src/main/java/org/dslul/openboard/inputmethod/compat/ViewOutlineProviderCompatUtils.kt
+++ b/app/src/main/java/org/dslul/openboard/inputmethod/compat/ViewOutlineProviderCompatUtils.kt
@@ -6,24 +6,44 @@
 
 package org.dslul.openboard.inputmethod.compat
 
+import android.graphics.Outline
 import android.inputmethodservice.InputMethodService
-import android.os.Build
-import android.os.Build.VERSION_CODES
 import android.view.View
+import android.view.ViewOutlineProvider
 
+// todo: this is not compat any more
 object ViewOutlineProviderCompatUtils {
-    private val EMPTY_INSETS_UPDATER: InsetsUpdater = object : InsetsUpdater {
-        override fun setInsets(insets: InputMethodService.Insets) {}
-    }
-
     @JvmStatic
-    fun setInsetsOutlineProvider(view: View): InsetsUpdater {
-        return if (Build.VERSION.SDK_INT < VERSION_CODES.LOLLIPOP) {
-            EMPTY_INSETS_UPDATER
-        } else ViewOutlineProviderCompatUtilsLXX.setInsetsOutlineProvider(view)
+    fun setInsetsOutlineProvider(view: View): InsetsOutlineProvider {
+        val provider = InsetsOutlineProvider(view)
+        view.outlineProvider = provider
+        return provider
+    }
+}
+
+class InsetsOutlineProvider(private val mView: View) : ViewOutlineProvider() {
+    private var mLastVisibleTopInsets = NO_DATA
+    init {
+        mView.outlineProvider = this
+    }
+    fun setInsets(insets: InputMethodService.Insets) {
+        val visibleTopInsets = insets.visibleTopInsets
+        if (mLastVisibleTopInsets != visibleTopInsets) {
+            mLastVisibleTopInsets = visibleTopInsets
+            mView.invalidateOutline()
+        }
     }
 
-    interface InsetsUpdater {
-        fun setInsets(insets: InputMethodService.Insets)
+    override fun getOutline(view: View, outline: Outline) {
+        if (mLastVisibleTopInsets == NO_DATA) { // Call default implementation.
+            BACKGROUND.getOutline(view, outline)
+            return
+        }
+        // TODO: Revisit this when floating/resize keyboard is supported.
+        outline.setRect(view.left, mLastVisibleTopInsets, view.right, view.bottom)
     }
-}
\ No newline at end of file
+
+    companion object {
+        private const val NO_DATA = -1
+    }
+}
diff --git a/app/src/main/java/org/dslul/openboard/inputmethod/compat/ViewOutlineProviderCompatUtilsLXX.kt b/app/src/main/java/org/dslul/openboard/inputmethod/compat/ViewOutlineProviderCompatUtilsLXX.kt
deleted file mode 100644
index b7f98c601..000000000
--- a/app/src/main/java/org/dslul/openboard/inputmethod/compat/ViewOutlineProviderCompatUtilsLXX.kt
+++ /dev/null
@@ -1,52 +0,0 @@
-/*
- * Copyright (C) 2014 The Android Open Source Project
- * modified
- * SPDX-License-Identifier: Apache-2.0 AND GPL-3.0-only
- */
-
-package org.dslul.openboard.inputmethod.compat
-
-import android.graphics.Outline
-import android.inputmethodservice.InputMethodService
-import android.os.Build
-import android.view.View
-import android.view.ViewOutlineProvider
-import androidx.annotation.RequiresApi
-import org.dslul.openboard.inputmethod.compat.ViewOutlineProviderCompatUtils.InsetsUpdater
-
-@RequiresApi(Build.VERSION_CODES.LOLLIPOP)
-internal object ViewOutlineProviderCompatUtilsLXX {
-    fun setInsetsOutlineProvider(view: View): InsetsUpdater {
-        val provider = InsetsOutlineProvider(view)
-        view.outlineProvider = provider
-        return provider
-    }
-
-    private class InsetsOutlineProvider(private val mView: View) : ViewOutlineProvider(), InsetsUpdater {
-        private var mLastVisibleTopInsets = NO_DATA
-        override fun setInsets(insets: InputMethodService.Insets) {
-            val visibleTopInsets = insets.visibleTopInsets
-            if (mLastVisibleTopInsets != visibleTopInsets) {
-                mLastVisibleTopInsets = visibleTopInsets
-                mView.invalidateOutline()
-            }
-        }
-
-        override fun getOutline(view: View, outline: Outline) {
-            if (mLastVisibleTopInsets == NO_DATA) { // Call default implementation.
-                BACKGROUND.getOutline(view, outline)
-                return
-            }
-            // TODO: Revisit this when floating/resize keyboard is supported.
-            outline.setRect(view.left, mLastVisibleTopInsets, view.right, view.bottom)
-        }
-
-        companion object {
-            private const val NO_DATA = -1
-        }
-
-        init {
-            mView.outlineProvider = this
-        }
-    }
-}
\ No newline at end of file
diff --git a/app/src/main/java/org/dslul/openboard/inputmethod/keyboard/KeyboardTheme.java b/app/src/main/java/org/dslul/openboard/inputmethod/keyboard/KeyboardTheme.java
index 4cb5b5e49..cf65cd199 100644
--- a/app/src/main/java/org/dslul/openboard/inputmethod/keyboard/KeyboardTheme.java
+++ b/app/src/main/java/org/dslul/openboard/inputmethod/keyboard/KeyboardTheme.java
@@ -23,7 +23,7 @@ import org.dslul.openboard.inputmethod.latin.utils.DeviceProtectedUtils;
 
 import java.util.Arrays;
 
-public final class KeyboardTheme implements Comparable<KeyboardTheme> {
+public final class KeyboardTheme {
 
     // old themes
     public static final String STYLE_MATERIAL = "Material";
@@ -59,43 +59,23 @@ public final class KeyboardTheme implements Comparable<KeyboardTheme> {
 
     /* package private for testing */
     static final KeyboardTheme[] KEYBOARD_THEMES = {
-            new KeyboardTheme(THEME_ID_HOLO_BASE, "HoloBase", R.style.KeyboardTheme_HoloBase,
-                    VERSION_CODES.BASE),
-            new KeyboardTheme(THEME_ID_LXX_BASE, "LXXBase", R.style.KeyboardTheme_LXX_Base,
-                    VERSION_CODES.LOLLIPOP),
-            new KeyboardTheme(THEME_ID_LXX_BASE_BORDER, "LXXBaseBorder", R.style.KeyboardTheme_LXX_Base_Border,
-                    VERSION_CODES.LOLLIPOP),
-            new KeyboardTheme(THEME_ID_ROUNDED_BASE, "RoundedBase", R.style.KeyboardTheme_Rounded_Base,
-                    VERSION_CODES.LOLLIPOP),
-            new KeyboardTheme(THEME_ID_ROUNDED_BASE_BORDER, "RoundedBaseBorder", R.style.KeyboardTheme_Rounded_Base_Border,
-                    VERSION_CODES.LOLLIPOP)
+            new KeyboardTheme(THEME_ID_HOLO_BASE, "HoloBase", R.style.KeyboardTheme_HoloBase),
+            new KeyboardTheme(THEME_ID_LXX_BASE, "LXXBase", R.style.KeyboardTheme_LXX_Base),
+            new KeyboardTheme(THEME_ID_LXX_BASE_BORDER, "LXXBaseBorder", R.style.KeyboardTheme_LXX_Base_Border),
+            new KeyboardTheme(THEME_ID_ROUNDED_BASE, "RoundedBase", R.style.KeyboardTheme_Rounded_Base),
+            new KeyboardTheme(THEME_ID_ROUNDED_BASE_BORDER, "RoundedBaseBorder", R.style.KeyboardTheme_Rounded_Base_Border)
     };
 
-    static {
-        // Sort {@link #KEYBOARD_THEME} by descending order of {@link #mMinApiVersion}.
-        Arrays.sort(KEYBOARD_THEMES);
-    }
-
     public final int mThemeId;
     public final int mStyleId;
     public final String mThemeName;
-    public final int mMinApiVersion;
 
     // Note: The themeId should be aligned with "themeId" attribute of Keyboard style
     // in values/themes-<style>.xml.
-    private KeyboardTheme(final int themeId, final String themeName, final int styleId,
-            final int minApiVersion) {
+    private KeyboardTheme(final int themeId, final String themeName, final int styleId) {
         mThemeId = themeId;
         mThemeName = themeName;
         mStyleId = styleId;
-        mMinApiVersion = minApiVersion;
-    }
-
-    @Override
-    public int compareTo(final KeyboardTheme rhs) {
-        if (mMinApiVersion > rhs.mMinApiVersion) return -1;
-        if (mMinApiVersion < rhs.mMinApiVersion) return 1;
-        return 0;
     }
 
     @Override
diff --git a/app/src/main/java/org/dslul/openboard/inputmethod/keyboard/internal/keyboard_parser/KeyboardParser.kt b/app/src/main/java/org/dslul/openboard/inputmethod/keyboard/internal/keyboard_parser/KeyboardParser.kt
index 6f11a2dea..5a171916b 100644
--- a/app/src/main/java/org/dslul/openboard/inputmethod/keyboard/internal/keyboard_parser/KeyboardParser.kt
+++ b/app/src/main/java/org/dslul/openboard/inputmethod/keyboard/internal/keyboard_parser/KeyboardParser.kt
@@ -672,10 +672,9 @@ abstract class KeyboardParser(private val params: KeyboardParams, private val co
         }
         // crappy workaround...
         val locale = when (params.mId.locale.toString().lowercase()) {
+            // todo: improve this when switching (rich input) subtype to use language tag
             "hi_zz" -> Locale("en", "IN")
-            "sr_zz" -> if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.LOLLIPOP)
-                    Locale.forLanguageTag("sr-Latn")
-                else params.mId.locale // todo: copy strings to sr-rZZ when definitely not increasing min SDK to 21
+            "sr_zz" -> Locale.forLanguageTag("sr-Latn")
             else -> params.mId.locale
         }
         return ril.runInLocale(context.resources, locale)
diff --git a/app/src/main/java/org/dslul/openboard/inputmethod/latin/LatinIME.java b/app/src/main/java/org/dslul/openboard/inputmethod/latin/LatinIME.java
index eab44495a..3be84da93 100644
--- a/app/src/main/java/org/dslul/openboard/inputmethod/latin/LatinIME.java
+++ b/app/src/main/java/org/dslul/openboard/inputmethod/latin/LatinIME.java
@@ -42,8 +42,8 @@ import android.view.inputmethod.InputMethodSubtype;
 import org.dslul.openboard.inputmethod.accessibility.AccessibilityUtils;
 import org.dslul.openboard.inputmethod.annotations.UsedForTesting;
 import org.dslul.openboard.inputmethod.compat.EditorInfoCompatUtils;
+import org.dslul.openboard.inputmethod.compat.InsetsOutlineProvider;
 import org.dslul.openboard.inputmethod.compat.ViewOutlineProviderCompatUtils;
-import org.dslul.openboard.inputmethod.compat.ViewOutlineProviderCompatUtils.InsetsUpdater;
 import org.dslul.openboard.inputmethod.dictionarypack.DictionaryPackConstants;
 import org.dslul.openboard.inputmethod.event.Event;
 import org.dslul.openboard.inputmethod.event.HangulEventDecoder;
@@ -142,7 +142,7 @@ public class LatinIME extends InputMethodService implements KeyboardActionListen
 
     // TODO: Move these {@link View}s to {@link KeyboardSwitcher}.
     private View mInputView;
-    private InsetsUpdater mInsetsUpdater;
+    private InsetsOutlineProvider mInsetsUpdater;
     private SuggestionStripView mSuggestionStripView;
 
     private RichInputMethodManager mRichImm;
@@ -2006,9 +2006,10 @@ public class LatinIME extends InputMethodService implements KeyboardActionListen
     }
 
     // slightly modified from Simple Keyboard: https://github.com/rkkr/simple-keyboard/blob/master/app/src/main/java/rkr/simplekeyboard/inputmethod/latin/LatinIME.java
+    @SuppressWarnings("deprecation")
     private void setNavigationBarColor() {
         final SettingsValues settingsValues = mSettings.getCurrent();
-        if (Build.VERSION.SDK_INT < Build.VERSION_CODES.LOLLIPOP || !settingsValues.mCustomNavBarColor)
+        if (!settingsValues.mCustomNavBarColor)
             return;
         final int color = settingsValues.mColors.get(ColorType.NAVIGATION_BAR);
         final Window window = getWindow().getWindow();
@@ -2031,7 +2032,7 @@ public class LatinIME extends InputMethodService implements KeyboardActionListen
     @SuppressWarnings("deprecation")
     private void clearNavigationBarColor() {
         final SettingsValues settingsValues = mSettings.getCurrent();
-        if (Build.VERSION.SDK_INT < Build.VERSION_CODES.LOLLIPOP || !settingsValues.mCustomNavBarColor)
+        if (!settingsValues.mCustomNavBarColor)
             return;
         final Window window = getWindow().getWindow();
         if (window == null) {
diff --git a/app/src/main/java/org/dslul/openboard/inputmethod/latin/RichInputConnection.java b/app/src/main/java/org/dslul/openboard/inputmethod/latin/RichInputConnection.java
index 57d4a0a2f..0427cba42 100644
--- a/app/src/main/java/org/dslul/openboard/inputmethod/latin/RichInputConnection.java
+++ b/app/src/main/java/org/dslul/openboard/inputmethod/latin/RichInputConnection.java
@@ -1176,14 +1176,11 @@ public final class RichInputConnection implements PrivateCommandPerformer {
      * prevents the application from fulfilling the request. (TODO: Improve the API when it turns
      * out that we actually need more detailed error codes)
      */
-    public boolean requestCursorUpdates(final boolean enableMonitor,
-            final boolean requestImmediateCallback) {
+    public boolean requestCursorUpdates(final boolean enableMonitor, final boolean requestImmediateCallback) {
         mIC = mParent.getCurrentInputConnection();
         if (!isConnected()) {
             return false;
         }
-        if (android.os.Build.VERSION.SDK_INT < android.os.Build.VERSION_CODES.LOLLIPOP)
-            return false;
         final int cursorUpdateMode = (enableMonitor ? InputConnection.CURSOR_UPDATE_MONITOR : 0)
             | (requestImmediateCallback ? InputConnection.CURSOR_UPDATE_IMMEDIATE : 0);
         return mIC.requestCursorUpdates(cursorUpdateMode);
diff --git a/app/src/main/java/org/dslul/openboard/inputmethod/latin/RichInputMethodSubtype.java b/app/src/main/java/org/dslul/openboard/inputmethod/latin/RichInputMethodSubtype.java
index 121c11d77..88eddc74e 100644
--- a/app/src/main/java/org/dslul/openboard/inputmethod/latin/RichInputMethodSubtype.java
+++ b/app/src/main/java/org/dslul/openboard/inputmethod/latin/RichInputMethodSubtype.java
@@ -33,6 +33,7 @@ import androidx.annotation.Nullable;
 public class RichInputMethodSubtype {
     private static final String TAG = RichInputMethodSubtype.class.getSimpleName();
 
+    // todo: remove this map when switching (rich input) subtype to use language tag
     private static final HashMap<Locale, Locale> sLocaleMap = initializeLocaleMap();
     private static HashMap<Locale, Locale> initializeLocaleMap() {
         final HashMap<Locale, Locale> map = new HashMap<>();
diff --git a/app/src/main/java/org/dslul/openboard/inputmethod/latin/SuggestedWords.java b/app/src/main/java/org/dslul/openboard/inputmethod/latin/SuggestedWords.java
index 60e12fca7..ffc77c5ff 100644
--- a/app/src/main/java/org/dslul/openboard/inputmethod/latin/SuggestedWords.java
+++ b/app/src/main/java/org/dslul/openboard/inputmethod/latin/SuggestedWords.java
@@ -90,11 +90,10 @@ public class SuggestedWords {
     /**
      * Get suggested word to show as suggestions to UI.
      *
-     * @param shouldShowLxxSuggestionUi true if showing suggestion UI introduced in LXX and later.
      * @return the count of suggested word to show as suggestions to UI.
      */
-    public int getWordCountToShow(final boolean shouldShowLxxSuggestionUi) {
-        if (isPrediction() || !shouldShowLxxSuggestionUi) {
+    public int getWordCountToShow() {
+        if (isPrediction()) {
             return size();
         }
         return size() - /* typed word */ 1;
diff --git a/app/src/main/java/org/dslul/openboard/inputmethod/latin/inputlogic/InputLogic.java b/app/src/main/java/org/dslul/openboard/inputmethod/latin/inputlogic/InputLogic.java
index 5f24fa05a..aa4006449 100644
--- a/app/src/main/java/org/dslul/openboard/inputmethod/latin/inputlogic/InputLogic.java
+++ b/app/src/main/java/org/dslul/openboard/inputmethod/latin/inputlogic/InputLogic.java
@@ -155,10 +155,7 @@ public final class InputLogic {
         } else {
             mInputLogicHandler.reset();
         }
-
-        if (settingsValues.mShouldShowLxxSuggestionUi) {
-            mConnection.requestCursorUpdates(true, true);
-        }
+        mConnection.requestCursorUpdates(true, true);
     }
 
     /**
diff --git a/app/src/main/java/org/dslul/openboard/inputmethod/latin/settings/AboutFragment.kt b/app/src/main/java/org/dslul/openboard/inputmethod/latin/settings/AboutFragment.kt
index df00d16ae..6c4da2d07 100644
--- a/app/src/main/java/org/dslul/openboard/inputmethod/latin/settings/AboutFragment.kt
+++ b/app/src/main/java/org/dslul/openboard/inputmethod/latin/settings/AboutFragment.kt
@@ -7,8 +7,6 @@ package org.dslul.openboard.inputmethod.latin.settings
 
 import android.app.Activity
 import android.content.Intent
-import android.graphics.Color
-import android.os.Build
 import android.os.Bundle
 import android.text.method.LinkMovementMethod
 import android.view.View
@@ -16,7 +14,6 @@ import android.widget.TextView
 import android.widget.Toast
 import androidx.activity.result.contract.ActivityResultContracts
 import androidx.appcompat.app.AlertDialog
-import androidx.core.graphics.drawable.DrawableCompat
 import androidx.preference.Preference
 import org.dslul.openboard.inputmethod.latin.BuildConfig
 import org.dslul.openboard.inputmethod.latin.R
@@ -31,15 +28,6 @@ class AboutFragment : SubScreenFragment() {
         super.onCreate(icicle)
         addPreferencesFromResource(R.xml.prefs_screen_about)
 
-        if (Build.VERSION.SDK_INT < Build.VERSION_CODES.LOLLIPOP) {
-            // need to set icon tint because old android versions don't use the vector drawables
-            for (i in 0 until preferenceScreen.preferenceCount) {
-                val p = preferenceScreen.getPreference(0)
-                val icon = p.icon
-                if (icon != null) DrawableCompat.setTint(icon, Color.WHITE)
-            }
-        }
-
         setupHiddenFeatures()
         setupVersionPref()
         findPreference<Preference>("log_reader")?.setOnPreferenceClickListener {
diff --git a/app/src/main/java/org/dslul/openboard/inputmethod/latin/settings/AdvancedSettingsFragment.kt b/app/src/main/java/org/dslul/openboard/inputmethod/latin/settings/AdvancedSettingsFragment.kt
index 6112e885d..b5003b234 100644
--- a/app/src/main/java/org/dslul/openboard/inputmethod/latin/settings/AdvancedSettingsFragment.kt
+++ b/app/src/main/java/org/dslul/openboard/inputmethod/latin/settings/AdvancedSettingsFragment.kt
@@ -120,11 +120,7 @@ class AdvancedSettingsFragment : SubScreenFragment() {
 
     private fun onClickLoadLibrary(): Boolean {
         // get architecture for telling user which file to use
-        val abi = if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.LOLLIPOP) {
-            Build.SUPPORTED_ABIS[0]
-        } else {
-            @Suppress("Deprecation") Build.CPU_ABI
-        }
+        val abi = Build.SUPPORTED_ABIS[0]
         // show delete / add dialog
         val builder = AlertDialog.Builder(requireContext())
                 .setTitle(R.string.load_gesture_library)
@@ -161,11 +157,7 @@ class AdvancedSettingsFragment : SubScreenFragment() {
             if (checksum == JniUtils.expectedDefaultChecksum()) {
                 renameToLibfileAndRestart(tmpfile, checksum)
             } else {
-                val abi = if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.LOLLIPOP) {
-                    Build.SUPPORTED_ABIS[0]
-                } else {
-                    @Suppress("Deprecation") Build.CPU_ABI
-                }
+                val abi = Build.SUPPORTED_ABIS[0]
                 AlertDialog.Builder(requireContext())
                     .setMessage(getString(R.string.checksum_mismatch_message, abi))
                     .setPositiveButton(android.R.string.ok) { _, _ -> renameToLibfileAndRestart(tmpfile, checksum) }
diff --git a/app/src/main/java/org/dslul/openboard/inputmethod/latin/settings/AppearanceSettingsFragment.kt b/app/src/main/java/org/dslul/openboard/inputmethod/latin/settings/AppearanceSettingsFragment.kt
index 62c0f6883..2d6b26663 100644
--- a/app/src/main/java/org/dslul/openboard/inputmethod/latin/settings/AppearanceSettingsFragment.kt
+++ b/app/src/main/java/org/dslul/openboard/inputmethod/latin/settings/AppearanceSettingsFragment.kt
@@ -12,7 +12,6 @@ import androidx.preference.TwoStatePreference
 import org.dslul.openboard.inputmethod.keyboard.KeyboardSwitcher
 import org.dslul.openboard.inputmethod.keyboard.KeyboardTheme
 import org.dslul.openboard.inputmethod.latin.R
-import org.dslul.openboard.inputmethod.latin.define.ProductionFlags
 import java.lang.Float.max
 import java.lang.Float.min
 import java.util.*
@@ -79,10 +78,6 @@ class AppearanceSettingsFragment : SubScreenFragment() {
                 removePreference("theme_select_colors_night")
             }
         }
-        if (Build.VERSION.SDK_INT < Build.VERSION_CODES.LOLLIPOP) {
-            // todo: consider removing the preference, and always set the navbar color
-            removePreference(Settings.PREF_NAVBAR_COLOR)
-        }
         val metrics = requireContext().resources.displayMetrics
         val widthDp = metrics.widthPixels / metrics.density
         val heightDp = metrics.heightPixels / metrics.density
diff --git a/app/src/main/java/org/dslul/openboard/inputmethod/latin/settings/DebugSettings.java b/app/src/main/java/org/dslul/openboard/inputmethod/latin/settings/DebugSettings.java
index c59b9609c..11b3e3e2f 100644
--- a/app/src/main/java/org/dslul/openboard/inputmethod/latin/settings/DebugSettings.java
+++ b/app/src/main/java/org/dslul/openboard/inputmethod/latin/settings/DebugSettings.java
@@ -12,7 +12,6 @@ package org.dslul.openboard.inputmethod.latin.settings;
 public final class DebugSettings {
     public static final String PREF_DEBUG_MODE = "debug_mode";
     public static final String PREF_FORCE_NON_DISTINCT_MULTITOUCH = "force_non_distinct_multitouch";
-    public static final String PREF_SHOULD_SHOW_LXX_SUGGESTION_UI = "pref_should_show_lxx_suggestion_ui";
     public static final String PREF_SLIDING_KEY_INPUT_PREVIEW = "pref_sliding_key_input_preview";
     public static final String PREF_SHOW_DEBUG_SETTINGS = "pref_show_debug_settings";
 
diff --git a/app/src/main/java/org/dslul/openboard/inputmethod/latin/settings/DebugSettingsFragment.java b/app/src/main/java/org/dslul/openboard/inputmethod/latin/settings/DebugSettingsFragment.java
index c73d0521c..3da5711cb 100644
--- a/app/src/main/java/org/dslul/openboard/inputmethod/latin/settings/DebugSettingsFragment.java
+++ b/app/src/main/java/org/dslul/openboard/inputmethod/latin/settings/DebugSettingsFragment.java
@@ -40,10 +40,6 @@ public final class DebugSettingsFragment extends SubScreenFragment
         super.onCreate(icicle);
         addPreferencesFromResource(R.xml.prefs_screen_debug);
 
-        if (!Settings.SHOULD_SHOW_LXX_SUGGESTION_UI) {
-            removePreference(DebugSettings.PREF_SHOULD_SHOW_LXX_SUGGESTION_UI);
-        }
-
         final PreferenceGroup dictDumpPreferenceGroup = findPreference(PREF_KEY_DUMP_DICTS);
         for (final String dictName : DictionaryFacilitatorImpl.DICT_TYPE_TO_CLASS.keySet()) {
             final Preference pref = new DictDumpPreference(getActivity(), dictName);
diff --git a/app/src/main/java/org/dslul/openboard/inputmethod/latin/settings/LanguageFilterList.kt b/app/src/main/java/org/dslul/openboard/inputmethod/latin/settings/LanguageFilterList.kt
index d3ab04712..74310ae49 100644
--- a/app/src/main/java/org/dslul/openboard/inputmethod/latin/settings/LanguageFilterList.kt
+++ b/app/src/main/java/org/dslul/openboard/inputmethod/latin/settings/LanguageFilterList.kt
@@ -13,8 +13,8 @@ import android.view.View
 import android.view.ViewGroup
 import android.widget.EditText
 import android.widget.LinearLayout
+import android.widget.Switch
 import android.widget.TextView
-import androidx.appcompat.widget.SwitchCompat
 import androidx.core.view.isGone
 import androidx.core.view.isVisible
 import androidx.core.widget.doAfterTextChanged
@@ -114,7 +114,7 @@ private class LanguageAdapter(list: List<MutableList<SubtypeInfo>> = listOf(), c
                         else isVisible = true
                 }
 
-                view.findViewById<SwitchCompat>(R.id.language_switch).apply {
+                view.findViewById<Switch>(R.id.language_switch).apply {
                     isEnabled = !onlySystemLocales
                     // take care: isChecked changes if the language is scrolled out of view and comes back!
                     // disable the change listener when setting the checked status on scroll
diff --git a/app/src/main/java/org/dslul/openboard/inputmethod/latin/settings/LanguageSettingsDialog.kt b/app/src/main/java/org/dslul/openboard/inputmethod/latin/settings/LanguageSettingsDialog.kt
index e0a6ae566..7efbd2e53 100644
--- a/app/src/main/java/org/dslul/openboard/inputmethod/latin/settings/LanguageSettingsDialog.kt
+++ b/app/src/main/java/org/dslul/openboard/inputmethod/latin/settings/LanguageSettingsDialog.kt
@@ -11,9 +11,9 @@ import android.view.LayoutInflater
 import android.view.View
 import android.widget.ImageView
 import android.widget.ScrollView
+import android.widget.Switch
 import android.widget.TextView
 import androidx.appcompat.app.AlertDialog
-import androidx.appcompat.widget.SwitchCompat
 import androidx.core.view.get
 import androidx.core.view.isGone
 import androidx.core.view.isVisible
@@ -170,7 +170,7 @@ class LanguageSettingsDialog(
         } else {
             row.findViewById<View>(R.id.language_details).isGone = true
         }
-        row.findViewById<SwitchCompat>(R.id.language_switch).apply {
+        row.findViewById<Switch>(R.id.language_switch).apply {
             isChecked = subtype.isEnabled
             isEnabled = !onlySystemLocales
             setOnCheckedChangeListener { _, b ->
@@ -186,7 +186,7 @@ class LanguageSettingsDialog(
             }
         }
         if (isAdditionalSubtype(subtype.subtype)) {
-            row.findViewById<SwitchCompat>(R.id.language_switch).isEnabled = true
+            row.findViewById<Switch>(R.id.language_switch).isEnabled = true
             row.findViewById<ImageView>(R.id.delete_button).apply {
                 isVisible = true
                 setOnClickListener {
diff --git a/app/src/main/java/org/dslul/openboard/inputmethod/latin/settings/LanguageSettingsFragment.kt b/app/src/main/java/org/dslul/openboard/inputmethod/latin/settings/LanguageSettingsFragment.kt
index 79d860a6a..cb4844296 100644
--- a/app/src/main/java/org/dslul/openboard/inputmethod/latin/settings/LanguageSettingsFragment.kt
+++ b/app/src/main/java/org/dslul/openboard/inputmethod/latin/settings/LanguageSettingsFragment.kt
@@ -12,9 +12,9 @@ import android.view.LayoutInflater
 import android.view.View
 import android.view.ViewGroup
 import android.view.inputmethod.InputMethodSubtype
+import android.widget.Switch
 import androidx.activity.result.contract.ActivityResultContracts
 import androidx.appcompat.app.AppCompatActivity
-import androidx.appcompat.widget.SwitchCompat
 import androidx.core.content.edit
 import androidx.fragment.app.Fragment
 import org.dslul.openboard.inputmethod.latin.R
@@ -37,7 +37,7 @@ class LanguageSettingsFragment : Fragment(R.layout.language_settings) {
     private val systemLocales = mutableListOf<Locale>()
     private lateinit var languageFilterList: LanguageFilterList
     private lateinit var sharedPreferences: SharedPreferences
-    private lateinit var systemOnlySwitch: SwitchCompat
+    private lateinit var systemOnlySwitch: Switch
     private val dictionaryLocales by lazy { getDictionaryLocales(requireContext()).mapTo(HashSet()) { it.languageConsideringZZ() } }
 
     private val dictionaryFilePicker = registerForActivityResult(ActivityResultContracts.StartActivityForResult()) {
diff --git a/app/src/main/java/org/dslul/openboard/inputmethod/latin/settings/PreferencesSettingsFragment.java b/app/src/main/java/org/dslul/openboard/inputmethod/latin/settings/PreferencesSettingsFragment.java
index 249de528c..372485de9 100644
--- a/app/src/main/java/org/dslul/openboard/inputmethod/latin/settings/PreferencesSettingsFragment.java
+++ b/app/src/main/java/org/dslul/openboard/inputmethod/latin/settings/PreferencesSettingsFragment.java
@@ -9,14 +9,10 @@ package org.dslul.openboard.inputmethod.latin.settings;
 import android.content.Context;
 import android.content.SharedPreferences;
 import android.content.res.Resources;
-import android.graphics.Color;
-import android.graphics.drawable.Drawable;
 import android.media.AudioManager;
-import android.os.Build;
 import android.os.Bundle;
 import android.view.inputmethod.InputMethodSubtype;
 
-import androidx.core.graphics.drawable.DrawableCompat;
 import androidx.preference.Preference;
 
 import org.dslul.openboard.inputmethod.keyboard.KeyboardLayoutSet;
@@ -39,16 +35,6 @@ public final class PreferencesSettingsFragment extends SubScreenFragment {
         super.onCreate(icicle);
         addPreferencesFromResource(R.xml.prefs_screen_preferences);
 
-        if (Build.VERSION.SDK_INT < Build.VERSION_CODES.LOLLIPOP) {
-            // need to set icon tint because old android versions don't use the vector drawables
-            for (int i = 0; i < getPreferenceScreen().getPreferenceCount(); i++) {
-                final Preference p = getPreferenceScreen().getPreference(0);
-                final Drawable icon = p.getIcon();
-                if (icon != null)
-                    DrawableCompat.setTint(icon, Color.WHITE);
-            }
-        }
-
         final Resources res = getResources();
         final Context context = getActivity();
 
diff --git a/app/src/main/java/org/dslul/openboard/inputmethod/latin/settings/Settings.java b/app/src/main/java/org/dslul/openboard/inputmethod/latin/settings/Settings.java
index da78c06d3..e4d9d7045 100644
--- a/app/src/main/java/org/dslul/openboard/inputmethod/latin/settings/Settings.java
+++ b/app/src/main/java/org/dslul/openboard/inputmethod/latin/settings/Settings.java
@@ -87,7 +87,6 @@ public final class Settings implements SharedPreferences.OnSharedPreferenceChang
     public static final String PREF_KEY_USE_PERSONALIZED_DICTS = "pref_key_use_personalized_dicts";
     public static final String PREF_KEY_USE_DOUBLE_SPACE_PERIOD = "pref_key_use_double_space_period";
     public static final String PREF_BLOCK_POTENTIALLY_OFFENSIVE = "pref_key_block_potentially_offensive";
-    public static final boolean SHOULD_SHOW_LXX_SUGGESTION_UI = Build.VERSION.SDK_INT >= Build.VERSION_CODES.LOLLIPOP;
     public static final String PREF_LANGUAGE_SWITCH_KEY = "pref_language_switch_key";
     public static final String PREF_SHOW_EMOJI_KEY = "pref_show_emoji_key";
     public static final String PREF_ADDITIONAL_SUBTYPES = "pref_additional_subtypes";
diff --git a/app/src/main/java/org/dslul/openboard/inputmethod/latin/settings/SettingsValues.java b/app/src/main/java/org/dslul/openboard/inputmethod/latin/settings/SettingsValues.java
index f941057f3..4ec969f41 100644
--- a/app/src/main/java/org/dslul/openboard/inputmethod/latin/settings/SettingsValues.java
+++ b/app/src/main/java/org/dslul/openboard/inputmethod/latin/settings/SettingsValues.java
@@ -96,8 +96,6 @@ public class SettingsValues {
     public final int mKeyLongpressTimeout;
     public final boolean mEnableEmojiAltPhysicalKey;
     public final boolean mIsShowAppIconSettingInPreferences;
-    public final boolean mShouldShowLxxSuggestionUi;
-    // Use split layout for keyboard.
     public final boolean mIsSplitKeyboardEnabled;
     public final float mSplitKeyboardSpacerRelativeWidth;
     public final int mScreenMetrics;
@@ -177,8 +175,6 @@ public class SettingsValues {
                 : 0f;
         mScreenMetrics = Settings.readScreenMetrics(res);
 
-        mShouldShowLxxSuggestionUi = Settings.SHOULD_SHOW_LXX_SUGGESTION_UI
-                && prefs.getBoolean(DebugSettings.PREF_SHOULD_SHOW_LXX_SUGGESTION_UI, true);
         // Compute other readable settings
         mKeyLongpressTimeout = Settings.readKeyLongpressTimeout(prefs, res);
         mKeypressVibrationDuration = Settings.readKeypressVibrationDuration(prefs, res);
diff --git a/app/src/main/java/org/dslul/openboard/inputmethod/latin/spellcheck/AndroidSpellCheckerSession.java b/app/src/main/java/org/dslul/openboard/inputmethod/latin/spellcheck/AndroidSpellCheckerSession.java
index a29d4ab5a..e946c0821 100644
--- a/app/src/main/java/org/dslul/openboard/inputmethod/latin/spellcheck/AndroidSpellCheckerSession.java
+++ b/app/src/main/java/org/dslul/openboard/inputmethod/latin/spellcheck/AndroidSpellCheckerSession.java
@@ -14,7 +14,6 @@ import android.view.textservice.SentenceSuggestionsInfo;
 import android.view.textservice.SuggestionsInfo;
 import android.view.textservice.TextInfo;
 
-import org.dslul.openboard.inputmethod.compat.TextInfoCompatUtils;
 import org.dslul.openboard.inputmethod.latin.NgramContext;
 import org.dslul.openboard.inputmethod.latin.utils.SpannableStringUtils;
 
@@ -34,7 +33,7 @@ public final class AndroidSpellCheckerSession extends AndroidWordLevelSpellCheck
 
     private SentenceSuggestionsInfo fixWronglyInvalidatedWordWithSingleQuote(TextInfo ti,
             SentenceSuggestionsInfo ssi) {
-        final CharSequence typedText = TextInfoCompatUtils.getCharSequenceOrString(ti);
+        final CharSequence typedText = ti.getCharSequence();
         if (!typedText.toString().contains(AndroidSpellCheckerService.SINGLE_QUOTE)) {
             return null;
         }
@@ -184,8 +183,7 @@ public final class AndroidSpellCheckerSession extends AndroidWordLevelSpellCheck
                 final CharSequence prevWord;
                 if (sequentialWords && i > 0) {
                     final TextInfo prevTextInfo = textInfos[i - 1];
-                    final CharSequence prevWordCandidate =
-                            TextInfoCompatUtils.getCharSequenceOrString(prevTextInfo);
+                    final CharSequence prevWordCandidate = prevTextInfo.getCharSequence();
                     // Note that an empty string would be used to indicate the initial word
                     // in the future.
                     prevWord = TextUtils.isEmpty(prevWordCandidate) ? null : prevWordCandidate;
diff --git a/app/src/main/java/org/dslul/openboard/inputmethod/latin/spellcheck/SentenceLevelAdapter.java b/app/src/main/java/org/dslul/openboard/inputmethod/latin/spellcheck/SentenceLevelAdapter.java
index 95ca9d88d..daf98a57d 100644
--- a/app/src/main/java/org/dslul/openboard/inputmethod/latin/spellcheck/SentenceLevelAdapter.java
+++ b/app/src/main/java/org/dslul/openboard/inputmethod/latin/spellcheck/SentenceLevelAdapter.java
@@ -11,7 +11,6 @@ import android.view.textservice.SentenceSuggestionsInfo;
 import android.view.textservice.SuggestionsInfo;
 import android.view.textservice.TextInfo;
 
-import org.dslul.openboard.inputmethod.compat.TextInfoCompatUtils;
 import org.dslul.openboard.inputmethod.latin.common.Constants;
 import org.dslul.openboard.inputmethod.latin.settings.SpacingAndPunctuations;
 import org.dslul.openboard.inputmethod.latin.utils.RunInLocale;
@@ -124,8 +123,7 @@ public class SentenceLevelAdapter {
 
     public SentenceTextInfoParams getSplitWords(TextInfo originalTextInfo) {
         final WordIterator wordIterator = mWordIterator;
-        final CharSequence originalText =
-                TextInfoCompatUtils.getCharSequenceOrString(originalTextInfo);
+        final CharSequence originalText = originalTextInfo.getCharSequence();
         final int cookie = originalTextInfo.getCookie();
         final int start = -1;
         final int end = originalText.length();
@@ -134,7 +132,7 @@ public class SentenceLevelAdapter {
         int wordEnd = wordIterator.getEndOfWord(originalText, wordStart);
         while (wordStart <= end && wordEnd != -1 && wordStart != -1) {
             if (wordEnd >= start && wordEnd > wordStart) {
-                final TextInfo ti = TextInfoCompatUtils.newInstance(originalText, wordStart,
+                final TextInfo ti = new TextInfo(originalText, wordStart,
                         wordEnd, cookie, originalText.subSequence(wordStart, wordEnd).hashCode());
                 wordItems.add(new SentenceWordItem(ti, wordStart, wordEnd));
             }
diff --git a/app/src/main/java/org/dslul/openboard/inputmethod/latin/suggestions/SuggestionStripLayoutHelper.java b/app/src/main/java/org/dslul/openboard/inputmethod/latin/suggestions/SuggestionStripLayoutHelper.java
index 368cf85f8..c98152221 100644
--- a/app/src/main/java/org/dslul/openboard/inputmethod/latin/suggestions/SuggestionStripLayoutHelper.java
+++ b/app/src/main/java/org/dslul/openboard/inputmethod/latin/suggestions/SuggestionStripLayoutHelper.java
@@ -225,11 +225,9 @@ final class SuggestionStripLayoutHelper {
             final SuggestedWords suggestedWords) {
         final SettingsValues settingsValues = Settings.getInstance().getCurrent();
         final boolean shouldOmitTypedWord = shouldOmitTypedWord(suggestedWords.mInputStyle,
-                settingsValues.mGestureFloatingPreviewTextEnabled,
-                settingsValues.mShouldShowLxxSuggestionUi);
+                settingsValues.mGestureFloatingPreviewTextEnabled, true);
         return getPositionInSuggestionStrip(indexInSuggestedWords, suggestedWords.mWillAutoCorrect,
-                settingsValues.mShouldShowLxxSuggestionUi && shouldOmitTypedWord,
-                mCenterPositionInStrip, mTypedWordPositionWhenAutocorrect);
+                shouldOmitTypedWord, mCenterPositionInStrip, mTypedWordPositionWhenAutocorrect);
     }
 
     @UsedForTesting
@@ -337,8 +335,7 @@ final class SuggestionStripLayoutHelper {
                     (PunctuationSuggestions)suggestedWords, stripView);
         }
 
-        final int wordCountToShow = suggestedWords.getWordCountToShow(
-                Settings.getInstance().getCurrent().mShouldShowLxxSuggestionUi);
+        final int wordCountToShow = suggestedWords.getWordCountToShow();
         final int startIndexOfMoreSuggestions = setupWordViewsAndReturnStartIndexOfMoreSuggestions(
                 suggestedWords, mSuggestionsCountInStrip);
         final TextView centerWordView = mWordViews.get(mCenterPositionInStrip);
diff --git a/app/src/main/java/org/dslul/openboard/inputmethod/latin/utils/CursorAnchorInfoUtils.java b/app/src/main/java/org/dslul/openboard/inputmethod/latin/utils/CursorAnchorInfoUtils.java
index f678ced72..990002b96 100644
--- a/app/src/main/java/org/dslul/openboard/inputmethod/latin/utils/CursorAnchorInfoUtils.java
+++ b/app/src/main/java/org/dslul/openboard/inputmethod/latin/utils/CursorAnchorInfoUtils.java
@@ -6,12 +6,10 @@
 
 package org.dslul.openboard.inputmethod.latin.utils;
 
-import android.annotation.TargetApi;
 import android.graphics.Matrix;
 import android.graphics.Rect;
 import android.inputmethodservice.ExtractEditText;
 import android.inputmethodservice.InputMethodService;
-import android.os.Build;
 import android.text.Layout;
 import android.text.Spannable;
 import android.text.Spanned;
@@ -23,8 +21,7 @@ import android.widget.TextView;
 import androidx.annotation.NonNull;
 import androidx.annotation.Nullable;
 
-import org.dslul.openboard.inputmethod.compat.CursorAnchorInfoCompatWrapper;
-
+// todo: remove this? or is there anything it could be useful for?
 /**
  * This class allows input methods to extract {@link CursorAnchorInfo} directly from the given
  * {@link TextView}. This is useful and even necessary to support full-screen mode where the default
@@ -74,30 +71,12 @@ public final class CursorAnchorInfoUtils {
         return true;
     }
 
-    /**
-     * Extracts {@link CursorAnchorInfoCompatWrapper} from the given {@link TextView}.
-     * @param textView the target text view from which {@link CursorAnchorInfoCompatWrapper} is to
-     * be extracted.
-     * @return the {@link CursorAnchorInfoCompatWrapper} object based on the current layout.
-     * {@code null} if {@code Build.VERSION.SDK_INT} is 20 or prior or {@link TextView} is not
-     * ready to provide layout information.
-     */
-    @Nullable
-    public static CursorAnchorInfoCompatWrapper extractFromTextView(
-            @NonNull final TextView textView) {
-        if (Build.VERSION.SDK_INT < Build.VERSION_CODES.LOLLIPOP) {
-            return null;
-        }
-        return CursorAnchorInfoCompatWrapper.wrap(extractFromTextViewInternal(textView));
-    }
-
     /**
      * Returns {@link CursorAnchorInfo} from the given {@link TextView}.
      * @param textView the target text view from which {@link CursorAnchorInfo} is to be extracted.
      * @return the {@link CursorAnchorInfo} object based on the current layout. {@code null} if it
      * is not feasible.
      */
-    @TargetApi(Build.VERSION_CODES.LOLLIPOP)
     @Nullable
     private static CursorAnchorInfo extractFromTextViewInternal(@NonNull final TextView textView) {
         final Layout layout = textView.getLayout();
diff --git a/app/src/main/java/org/dslul/openboard/inputmethod/latin/utils/JniUtils.java b/app/src/main/java/org/dslul/openboard/inputmethod/latin/utils/JniUtils.java
index d950ae83e..20a6c82e6 100644
--- a/app/src/main/java/org/dslul/openboard/inputmethod/latin/utils/JniUtils.java
+++ b/app/src/main/java/org/dslul/openboard/inputmethod/latin/utils/JniUtils.java
@@ -26,7 +26,7 @@ public final class JniUtils {
     private static final String CHECKSUM_X86 = "bd946d126c957b5a6dea3bafa07fa36a27950b30e2b684dffc60746d0a1c7ad8";
 
     public static String expectedDefaultChecksum() {
-        final String abi = Build.VERSION.SDK_INT >= Build.VERSION_CODES.LOLLIPOP ? Build.SUPPORTED_ABIS[0] : Build.CPU_ABI;
+        final String abi = Build.SUPPORTED_ABIS[0];
         return switch (abi) {
             case "arm64-v8a" -> CHECKSUM_ARM64;
             case "armeabi-v7a" -> CHECKSUM_ARM32;
diff --git a/app/src/main/java/org/dslul/openboard/inputmethod/latin/utils/MoreKeysUtils.kt b/app/src/main/java/org/dslul/openboard/inputmethod/latin/utils/MoreKeysUtils.kt
index fe259afa8..dcf6f1b64 100644
--- a/app/src/main/java/org/dslul/openboard/inputmethod/latin/utils/MoreKeysUtils.kt
+++ b/app/src/main/java/org/dslul/openboard/inputmethod/latin/utils/MoreKeysUtils.kt
@@ -5,9 +5,9 @@ import android.content.Context
 import android.content.SharedPreferences
 import android.view.LayoutInflater
 import android.view.ViewGroup
+import android.widget.Switch
 import android.widget.TextView
 import androidx.appcompat.app.AlertDialog
-import androidx.appcompat.widget.SwitchCompat
 import androidx.core.content.ContextCompat
 import androidx.recyclerview.widget.DiffUtil
 import androidx.recyclerview.widget.ItemTouchHelper
@@ -135,7 +135,7 @@ fun reorderMoreKeysDialog(context: Context, key: String, defaultSetting: String,
             val displayTextId = context.resources.getIdentifier(text.lowercase(), "string", context.packageName)
             val displayText = if (displayTextId == 0) text else context.getString(displayTextId)
             p0.itemView.findViewById<TextView>(R.id.morekeys_type)?.text = displayText
-            val switch = p0.itemView.findViewById<SwitchCompat>(R.id.morekeys_switch)
+            val switch = p0.itemView.findViewById<Switch>(R.id.morekeys_switch)
             switch?.isChecked = wasChecked
             switch?.isEnabled = !(key.contains(Settings.PREF_MORE_KEYS_ORDER) && text == MORE_KEYS_LAYOUT) // layout can't be disabled
             switch?.setOnCheckedChangeListener { _, isChecked ->
diff --git a/app/src/main/res/layout/color_setting.xml b/app/src/main/res/layout/color_setting.xml
index 012423f9b..f73865e19 100644
--- a/app/src/main/res/layout/color_setting.xml
+++ b/app/src/main/res/layout/color_setting.xml
@@ -34,7 +34,7 @@
             android:paddingHorizontal="10dp"
             style="@style/PreferenceSubtitleText" />
     </LinearLayout>
-    <androidx.appcompat.widget.SwitchCompat
+    <Switch
         android:id="@+id/color_switch"
         android:layout_gravity="center_vertical"
         android:layout_width="0dp"
diff --git a/app/src/main/res/layout/language_list_item.xml b/app/src/main/res/layout/language_list_item.xml
index d51216682..47755b11a 100644
--- a/app/src/main/res/layout/language_list_item.xml
+++ b/app/src/main/res/layout/language_list_item.xml
@@ -40,7 +40,7 @@
     <RelativeLayout
         android:layout_width="wrap_content"
         android:layout_height="wrap_content" >
-        <androidx.appcompat.widget.SwitchCompat
+        <Switch
             android:id="@+id/language_switch"
             android:padding="6dp"
             android:layout_gravity="center_vertical"
diff --git a/app/src/main/res/layout/language_settings.xml b/app/src/main/res/layout/language_settings.xml
index 6aa9ececa..faf72a68a 100644
--- a/app/src/main/res/layout/language_settings.xml
+++ b/app/src/main/res/layout/language_settings.xml
@@ -7,7 +7,7 @@
     android:paddingTop="6dp"
     android:layout_width="match_parent"
     android:layout_height="match_parent">
-    <androidx.appcompat.widget.SwitchCompat
+    <Switch
         android:id="@+id/language_switch"
         android:text="@string/use_system_language_to_select_input_method_subtypes"
         style="@style/PreferenceTitleText"
diff --git a/app/src/main/res/layout/morekeys_list_item.xml b/app/src/main/res/layout/morekeys_list_item.xml
index a7cf5ef8d..27152ef2a 100644
--- a/app/src/main/res/layout/morekeys_list_item.xml
+++ b/app/src/main/res/layout/morekeys_list_item.xml
@@ -17,7 +17,7 @@
         android:layout_width="0dp"
         android:layout_weight="1"
         android:layout_height="wrap_content" />
-    <androidx.appcompat.widget.SwitchCompat
+    <Switch
         android:id="@+id/morekeys_switch"
         android:padding="6dp"
         android:layout_gravity="center_vertical"
diff --git a/app/src/main/res/values-v21/platform-theme.xml b/app/src/main/res/values-v21/platform-theme.xml
deleted file mode 100644
index 1b92e18d7..000000000
--- a/app/src/main/res/values-v21/platform-theme.xml
+++ /dev/null
@@ -1,13 +0,0 @@
-<?xml version="1.0" encoding="utf-8"?>
-<!--
-    Copyright (C) 2014 The Android Open Source Project
-    modified
-    SPDX-License-Identifier: Apache-2.0 AND GPL-3.0-only
--->
-
-<resources xmlns:android="http://schemas.android.com/apk/res/android">
-    <style name="platformActivityTheme" parent="Theme.AppCompat.DayNight">
-        <item name="android:colorAccent">@color/accent</item>
-        <item name="colorAccent">@color/accent</item>
-    </style>
-</resources>
diff --git a/app/src/main/res/values-v21/themes-lxx.xml b/app/src/main/res/values-v21/themes-lxx.xml
deleted file mode 100644
index 91a851a86..000000000
--- a/app/src/main/res/values-v21/themes-lxx.xml
+++ /dev/null
@@ -1,14 +0,0 @@
-<?xml version="1.0" encoding="utf-8"?>
-<!--
-    Copyright (C) 2014 The Android Open Source Project
-    SPDX-License-Identifier: Apache-2.0
--->
-
-<resources xmlns:android="http://schemas.android.com/apk/res/android">
-    <style
-        name="InputView.LXX"
-        parent="InputView"
-    >
-        <item name="android:elevation">8dp</item>
-    </style>
-</resources>
diff --git a/app/src/main/res/values/donottranslate-debug-settings.xml b/app/src/main/res/values/donottranslate-debug-settings.xml
index 9b805978d..59653f916 100644
--- a/app/src/main/res/values/donottranslate-debug-settings.xml
+++ b/app/src/main/res/values/donottranslate-debug-settings.xml
@@ -12,7 +12,6 @@
     <string name="prefs_debug_mode" translatable="false">Debug Mode</string>
     <string name="prefs_show_suggestion_infos" translatable="false">Show suggestion infos</string>
     <string name="prefs_force_non_distinct_multitouch" translatable="false">Force non-distinct multitouch</string>
-    <string name="prefs_should_show_lxx_suggestion_ui" translatable="false">Show LXX suggestion UI</string>
     <!-- Option to enable sliding key input indicator. The user can see a rubber band-like effect during sliding key input. [CHAR LIMIT=30]-->
     <string name="sliding_key_input_preview" translatable="false">Show slide indicator</string>
     <!-- Option summary to enable sliding key input indicator. The user can see a rubber band-like effect during sliding key input. [CHAR LIMIT=66]-->
diff --git a/app/src/main/res/values/platform-theme.xml b/app/src/main/res/values/platform-theme.xml
index 9a4bbc434..1b92e18d7 100644
--- a/app/src/main/res/values/platform-theme.xml
+++ b/app/src/main/res/values/platform-theme.xml
@@ -6,5 +6,8 @@
 -->
 
 <resources xmlns:android="http://schemas.android.com/apk/res/android">
-    <style name="platformActivityTheme" parent="Theme.AppCompat.DayNight" />
+    <style name="platformActivityTheme" parent="Theme.AppCompat.DayNight">
+        <item name="android:colorAccent">@color/accent</item>
+        <item name="colorAccent">@color/accent</item>
+    </style>
 </resources>
diff --git a/app/src/main/res/values/themes-lxx.xml b/app/src/main/res/values/themes-lxx.xml
index 127f168a8..d95fde227 100644
--- a/app/src/main/res/values/themes-lxx.xml
+++ b/app/src/main/res/values/themes-lxx.xml
@@ -8,7 +8,9 @@
     <style
         name="InputView.LXX"
         parent="InputView"
-    />
+    >
+        <item name="android:elevation">8dp</item>
+    </style>
     <!-- LXX KeyboardView theme -->
     <style
         name="KeyboardView.LXX"
diff --git a/app/src/main/res/xml/prefs_screen_debug.xml b/app/src/main/res/xml/prefs_screen_debug.xml
index c5f12e3ca..2d73e19b8 100644
--- a/app/src/main/res/xml/prefs_screen_debug.xml
+++ b/app/src/main/res/xml/prefs_screen_debug.xml
@@ -28,11 +28,6 @@
         android:title="@string/prefs_force_non_distinct_multitouch"
         android:defaultValue="false"
         android:persistent="true" />
-    <SwitchPreferenceCompat
-        android:key="pref_should_show_lxx_suggestion_ui"
-        android:title="@string/prefs_should_show_lxx_suggestion_ui"
-        android:defaultValue="true"
-        android:persistent="true" />
     <SwitchPreferenceCompat
         android:key="pref_sliding_key_input_preview"
         android:title="@string/sliding_key_input_preview"