diff --git a/app/src/main/java/com/finnmglas/launcher/ChooseActivity.kt b/app/src/main/java/com/finnmglas/launcher/ChooseActivity.kt
index 56a9e97..d59dd5c 100644
--- a/app/src/main/java/com/finnmglas/launcher/ChooseActivity.kt
+++ b/app/src/main/java/com/finnmglas/launcher/ChooseActivity.kt
@@ -25,6 +25,13 @@ class ChooseActivity : AppCompatActivity() {
         window.setFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN, WindowManager.LayoutParams.FLAG_FULLSCREEN)
         window.addFlags(WindowManager.LayoutParams.FLAG_KEEP_SCREEN_ON)
 
+        setTheme(
+            when (getSavedTheme(this)) {
+                "dark" -> R.style.darkTheme
+                "finn" -> R.style.finnmglasTheme
+                else -> R.style.finnmglasTheme
+            }
+        )
         setContentView(R.layout.activity_choose)
 
         // As older APIs somehow do not recognize the xml defined onClick
diff --git a/app/src/main/java/com/finnmglas/launcher/FirstStartupActivity.kt b/app/src/main/java/com/finnmglas/launcher/FirstStartupActivity.kt
index e849653..58e9399 100644
--- a/app/src/main/java/com/finnmglas/launcher/FirstStartupActivity.kt
+++ b/app/src/main/java/com/finnmglas/launcher/FirstStartupActivity.kt
@@ -31,6 +31,13 @@ class FirstStartupActivity : AppCompatActivity(){
         )
         window.addFlags(WindowManager.LayoutParams.FLAG_KEEP_SCREEN_ON)
 
+        setTheme(
+            when (getSavedTheme(this)) {
+                "dark" -> R.style.darkTheme
+                "finn" -> R.style.finnmglasTheme
+                else -> R.style.finnmglasTheme
+            }
+        )
         setContentView(R.layout.activity_firststartup)
 
         hintText.blink() // animate
diff --git a/app/src/main/java/com/finnmglas/launcher/Functions.kt b/app/src/main/java/com/finnmglas/launcher/Functions.kt
index cf92058..5818569 100644
--- a/app/src/main/java/com/finnmglas/launcher/Functions.kt
+++ b/app/src/main/java/com/finnmglas/launcher/Functions.kt
@@ -124,6 +124,22 @@ fun openNewTabWindow(urls: String, context : Context) {
 
 /** Settings related functions */
 
+fun getSavedTheme(context : Context) : String {
+    val sharedPref = context.getSharedPreferences(
+        context.getString(R.string.preference_file_key), Context.MODE_PRIVATE)
+
+    return sharedPref.getString("theme", "finnmglas").toString()
+}
+
+fun saveTheme(context : Context, themeName : String) {
+    val sharedPref = context.getSharedPreferences(
+        context.getString(R.string.preference_file_key), Context.MODE_PRIVATE)
+
+    val editor: SharedPreferences.Editor = sharedPref.edit()
+    editor.putString("theme", themeName)
+    editor.apply()
+}
+
 fun openAppSettings(pkg :String, context:Context){
     val intent = Intent(Settings.ACTION_APPLICATION_DETAILS_SETTINGS)
     intent.data = Uri.parse("package:$pkg")
diff --git a/app/src/main/java/com/finnmglas/launcher/MainActivity.kt b/app/src/main/java/com/finnmglas/launcher/MainActivity.kt
index 2a48e33..66fb2eb 100644
--- a/app/src/main/java/com/finnmglas/launcher/MainActivity.kt
+++ b/app/src/main/java/com/finnmglas/launcher/MainActivity.kt
@@ -17,6 +17,8 @@ import kotlin.math.abs
 class MainActivity : AppCompatActivity(),
     GestureDetector.OnGestureListener, GestureDetector.OnDoubleTapListener {
 
+    private var currentTheme = "" // keep track of theme changes
+
     /** Variables for this activity */
     private lateinit var mDetector: GestureDetectorCompat
 
@@ -45,6 +47,14 @@ class MainActivity : AppCompatActivity(),
         )
         window.addFlags(WindowManager.LayoutParams.FLAG_KEEP_SCREEN_ON)
 
+        currentTheme = getSavedTheme(this)
+        setTheme(
+            when (currentTheme) {
+                "dark" -> R.style.darkTheme
+                "finn" -> R.style.finnmglasTheme
+                else -> R.style.finnmglasTheme
+            }
+        )
         setContentView(R.layout.activity_main)
 
         // Start by showing the settings icon
@@ -78,6 +88,8 @@ class MainActivity : AppCompatActivity(),
     override fun onResume() {
         super.onResume()
 
+        if (currentTheme != getSavedTheme(this)) recreate()
+
         val dateFormat = SimpleDateFormat("yyyy-MM-dd", Locale.getDefault())
         val timeFormat = SimpleDateFormat("HH:mm:ss", Locale.getDefault())
 
diff --git a/app/src/main/java/com/finnmglas/launcher/SettingsActivity.kt b/app/src/main/java/com/finnmglas/launcher/SettingsActivity.kt
index f068b94..35e4e5e 100644
--- a/app/src/main/java/com/finnmglas/launcher/SettingsActivity.kt
+++ b/app/src/main/java/com/finnmglas/launcher/SettingsActivity.kt
@@ -22,6 +22,15 @@ class SettingsActivity : AppCompatActivity() {
 
     override fun onCreate(savedInstanceState: Bundle?) {
         super.onCreate(savedInstanceState)
+
+        setTheme(
+            when (getSavedTheme(this)) {
+                "dark" -> R.style.darkTheme
+                "finn" -> R.style.finnmglasTheme
+                else -> R.style.finnmglasTheme
+            }
+        )
+
         setContentView(R.layout.activity_settings)
 
         window.setFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN, WindowManager.LayoutParams.FLAG_FULLSCREEN)
@@ -178,14 +187,18 @@ class SettingsActivity : AppCompatActivity() {
     /** Theme - related */
 
     fun chooseDarkTheme(view: View) {
-
+        saveTheme(this, "dark")
+        recreate()
     }
 
     fun chooseFinnTheme(view: View) {
-
+        saveTheme(this, "finn")
+        recreate()
     }
 
     fun chooseCustomTheme(view: View) {
-
+        Toast.makeText(this, "[not implemented yet]", Toast.LENGTH_SHORT)
+            .show()
     }
+
 }
diff --git a/app/src/main/res/values/styles.xml b/app/src/main/res/values/styles.xml
index 7010e55..0d1f376 100644
--- a/app/src/main/res/values/styles.xml
+++ b/app/src/main/res/values/styles.xml
@@ -13,6 +13,7 @@
         <item name="colorButtonNormal">@color/finnmglasTheme_accent_color</item>
 
         <item name="android:windowDisablePreview">true</item>
+        <item name="android:windowAnimationStyle">@style/WindowFadeTransition</item>
     </style>
 
     <!-- A dark efficiency theme -->
@@ -27,10 +28,16 @@
         <item name="colorButtonNormal">@color/darkTheme_accent_color</item>
 
         <item name="android:windowDisablePreview">true</item>
+        <item name="android:windowAnimationStyle">@style/WindowFadeTransition</item>
     </style>
 
     <style name="AlertDialogCustom" parent="Theme.AppCompat.Light.Dialog.Alert">
         <item name="android:textColor">#000000</item>
     </style>
 
+    <!-- Set the fade in animation on all activities by default -->
+    <style name="WindowFadeTransition">
+        <item name="android:windowEnterAnimation">@android:anim/fade_in</item>
+        <item name="android:windowExitAnimation">@android:anim/fade_out</item>
+    </style>
 </resources>