Use AppCompat theme.

app/build.gradle

@@ -11,7 +11,7 @@ buildscript {
 }
 
 dependencies {
-    compile "com.android.support:support-v4:22.0.0"
+    compile "com.android.support:appcompat-v7:22.0.0"
     compile 'com.android.support:multidex:1.0.1'
     androidTestCompile "com.android.support:multidex-instrumentation:1.0.1", { exclude module: "multidex" }
     compile "org.scala-lang:scala-library:2.11.6"

app/src/main/AndroidManifest.xml

@@ -37,7 +37,7 @@
 
         <activity
             android:name=".activities.ConfirmAddContactActivity"
-            android:theme="@android:style/Theme.Translucent.NoTitleBar"
+            android:theme="@style/Translucent"
             android:excludeFromRecents="true" />
 
         <activity

app/src/main/res/menu/main.xml

@@ -1,12 +1,13 @@
 <?xml version="1.0" encoding="utf-8"?>
 
-<menu xmlns:android="http://schemas.android.com/apk/res/android">
+<menu xmlns:android="http://schemas.android.com/apk/res/android"
+    xmlns:app="http://schemas.android.com/apk/res-auto">
 
     <item
         android:id="@+id/add_contact"
         android:title="@string/add_contacts"
         android:icon="@drawable/ic_action_add_person"
-        android:showAsAction="ifRoom" />
+        app:showAsAction="ifRoom" />
 
     <item
         android:id="@+id/settings"

app/src/main/res/values-v21/style.xml

@@ -1,5 +0,0 @@
-<?xml version="1.0" encoding="utf-8"?>
-
-<resources>
-    <style name="AppTheme" parent="@android:style/Theme.Material.Light.DarkActionBar" />
-</resources>

app/src/main/res/values/style.xml

@@ -1,5 +1,15 @@
 <?xml version="1.0" encoding="utf-8"?>
 
 <resources>
-    <style name="AppTheme" parent="android:Theme.DeviceDefault.Light.DarkActionBar" />
+
+    <style name="AppTheme" parent="@style/Theme.AppCompat.Light.DarkActionBar" />
+
+    <style name="Translucent" parent="AppTheme">
+        <item name="android:windowNoTitle">true</item>
+        <item name="android:windowBackground">@android:color/transparent</item>
+        <item name="android:colorBackgroundCacheHint">@null</item>
+        <item name="android:windowIsTranslucent">true</item>
+        <item name="android:windowAnimationStyle">@android:style/Animation</item>
+    </style>
+
 </resources>

app/src/main/scala/com/nutomic/ensichat/activities/AddContactsActivity.scala

@@ -29,7 +29,7 @@ class AddContactsActivity extends EnsiChatActivity with ChatService.OnConnection
    */
   override def onCreate(savedInstanceState: Bundle): Unit = {
     super.onCreate(savedInstanceState)
-    getActionBar.setDisplayHomeAsUpEnabled(true)
+    getSupportActionBar.setDisplayHomeAsUpEnabled(true)
 
     setContentView(R.layout.activity_add_contacts)
     val list = findViewById(android.R.id.list).asInstanceOf[ListView]

app/src/main/scala/com/nutomic/ensichat/activities/EnsiChatActivity.scala

@@ -3,12 +3,13 @@ package com.nutomic.ensichat.activities
 import android.app.Activity
 import android.content.{ComponentName, Context, Intent, ServiceConnection}
 import android.os.{Bundle, IBinder}
+import android.support.v7.app.ActionBarActivity
 import com.nutomic.ensichat.protocol.{ChatService, ChatServiceBinder}
 
 /**
  * Connects to [[ChatService]] and provides access to it.
  */
-class EnsiChatActivity extends Activity with ServiceConnection {
+class EnsiChatActivity extends ActionBarActivity with ServiceConnection {
 
   private var chatService: Option[ChatService] = None
 

app/src/main/scala/com/nutomic/ensichat/activities/MainActivity.scala

@@ -90,7 +90,7 @@ class MainActivity extends EnsiChatActivity {
       .detach(contactsFragment)
       .add(android.R.id.content, new ChatFragment(address))
       .commit()
-    getActionBar.setDisplayHomeAsUpEnabled(true)
+    getSupportActionBar.setDisplayHomeAsUpEnabled(true)
   }
 
   /**
@@ -104,7 +104,7 @@ class MainActivity extends EnsiChatActivity {
         .attach(contactsFragment)
         .commit()
       currentChat = None
-      getActionBar.setDisplayHomeAsUpEnabled(false)
+      getSupportActionBar.setDisplayHomeAsUpEnabled(false)
       setTitle(R.string.app_name)
     } else
       super.onBackPressed()

app/src/main/scala/com/nutomic/ensichat/activities/SettingsActivity.scala

@@ -15,7 +15,7 @@ class SettingsActivity extends EnsiChatActivity {
 
   override def onCreate(savedInstanceState: Bundle): Unit = {
     super.onCreate(savedInstanceState)
-    getActionBar.setDisplayHomeAsUpEnabled(true)
+    getSupportActionBar.setDisplayHomeAsUpEnabled(true)
 
     val fm = getFragmentManager
     fragment =