diff --git a/app/build.gradle.kts b/app/build.gradle.kts
index 63a6902..f29eafc 100644
--- a/app/build.gradle.kts
+++ b/app/build.gradle.kts
@@ -9,20 +9,20 @@ val keystoreProperties = Properties ()
 keystoreProperties . load ( FileInputStream ( rootProject . file ("keystore.properties") ) )
 
 plugins {
-	id ("com.android.application") . version ("8.8.0")
-	id ("org.jetbrains.kotlin.android") . version ("2.1.10")
-	id ("org.jetbrains.kotlin.plugin.compose") . version ("2.1.10")
-	id ("org.jetbrains.kotlin.plugin.serialization") . version ("2.1.10")
+	id ("com.android.application") . version ("8.7.2")
+	id ("org.jetbrains.kotlin.android") . version ("2.0.0")
+	id ("org.jetbrains.kotlin.plugin.compose") . version ("2.0.0")
+	id ("org.jetbrains.kotlin.plugin.serialization") . version ("2.0.0")
 }
 
 android {
 	namespace = "com.kernelmaft.zanbur"
-	compileSdk = 35
+	compileSdk = 34
 
 	defaultConfig {
 		applicationId = "com.kernelmaft.zanbur"
-		minSdk = 35
-		targetSdk = 35
+		minSdk = 31
+		targetSdk = 34
 		versionCode = 1
 		versionName = "1.0"
 	}
@@ -47,11 +47,10 @@ android {
 		}
 	}
 	compileOptions {
-		// Required even though we don't have any Java sources because it needs to match Kotlin's JVM version
-		targetCompatibility = JavaVersion . VERSION_23
+		targetCompatibility = JavaVersion . VERSION_11
 	}
 	kotlinOptions {
-		jvmTarget = "23"
+		jvmTarget = "11"
 	}
 	buildFeatures {
 		compose = true
@@ -61,18 +60,19 @@ android {
 dependencies {
 	// Android runtime libraries
 	implementation ( "com.google.android.material" , "material" , "1.12.0" )
-	implementation ( "androidx.activity" , "activity-compose" , "1.10.0" )
-	implementation ( "androidx.core" , "core-ktx" , "1.15.0" )
+	implementation ( "androidx.activity" , "activity-compose" , "1.9.3" )
+	implementation ( "androidx.core" , "core-ktx" , "1.13.1" )
 	implementation ( "androidx.compose.material3" , "material3" , "1.3.1" )
-	implementation ( "androidx.compose.ui" , "ui" , "1.7.7" )
-	implementation ( "androidx.compose.ui" , "ui-graphics" , "1.7.7" )
-	debugImplementation ( "androidx.compose.ui" , "ui-tooling" , "1.7.7" )
+	implementation ( "androidx.compose.ui" , "ui" , "1.7.5" )
+	implementation ( "androidx.compose.ui" , "ui-graphics" , "1.7.5" )
+	debugImplementation ( "androidx.compose.ui" , "ui-tooling" , "1.7.5" )
+	implementation ( "androidx.datastore" , "datastore-preferences" , "1.1.1" )
 	implementation ( "androidx.lifecycle" , "lifecycle-runtime-ktx" , "2.8.7" )
-	implementation ( "org.jetbrains.kotlinx" , "kotlinx-coroutines-android" , "1.10.1" )
-	implementation ( "org.jetbrains.kotlinx" , "kotlinx-serialization-json" , "1.8.0" )
+	implementation ( "org.jetbrains.kotlinx" , "kotlinx-coroutines-android" , "1.9.0" )
+	implementation ( "org.jetbrains.kotlinx" , "kotlinx-serialization-json" , "1.7.3" )
 	// Other libraries
-	implementation ( "io.github.davidepianca98" , "kmqtt-common" , "1.0.0" )
-	implementation ( "io.github.davidepianca98" , "kmqtt-client" , "1.0.0" )
+	implementation ( "io.github.davidepianca98" , "kmqtt-common" , "0.4.8" )
+	implementation ( "io.github.davidepianca98" , "kmqtt-client" , "0.4.8" )
 }
 
 tasks . withType ( KotlinCompile :: class ) . all {
diff --git a/app/src/main/AndroidManifest.xml b/app/src/main/AndroidManifest.xml
index 90a24a3..1acccf6 100644
--- a/app/src/main/AndroidManifest.xml
+++ b/app/src/main/AndroidManifest.xml
@@ -4,14 +4,17 @@
 	<uses-permission android:name = "android.permission.INTERNET" />
 
 	<application
-		android:label = "Zanbur"
 		android:icon = "@mipmap/ic_launcher"
+		android:label = "@string/app_name"
 		android:roundIcon = "@mipmap/ic_launcher_round"
-		android:supportsRtl = "true" >
+		android:supportsRtl = "true"
+		android:theme = "@style/Theme.Zanbur" >
 
 		<activity
-			android:name = "com.kernelmaft.zanbur.ui.MainActivity"
-			android:exported = "true" >
+			android:name = ".MainActivity"
+			android:exported = "true"
+			android:label = "@string/title_activity_main"
+			android:theme = "@style/Theme.Zanbur" >
 
 			<intent-filter>
 				<action android:name = "android.intent.action.MAIN" />
diff --git a/app/src/main/java/com/kernelmaft/zanbur/app-state.kt b/app/src/main/java/com/kernelmaft/zanbur/app-state.kt
new file mode 100644
index 0000000..52c4991
--- /dev/null
+++ b/app/src/main/java/com/kernelmaft/zanbur/app-state.kt
@@ -0,0 +1,25 @@
+package com.kernelmaft.zanbur
+
+
+
+object AppState {
+	val groups : List <Group> get () = groupsAsMutable
+	private var groupsAsMutable : List <Group> = emptyList ()
+
+	private val subscribers : MutableList < ( List <Group> ) -> Unit > = mutableListOf ()
+
+	fun subscribe ( subscriber : ( List <Group> ) -> Unit ) = subscribers . add (subscriber)
+
+	fun addGroup ( group : Group ) {
+		groupsAsMutable += group
+		subscribers . forEach { it (groups) }
+	}
+
+	fun setCurrentScene ( groupId : Int , scene : Scene ) {
+		groupsAsMutable = groupsAsMutable . mapIndexed { index , group ->
+			if ( index == groupId ) group . copy ( currentScene = scene )
+			else group
+		}
+		subscribers . forEach { it (groups) }
+	}
+}
diff --git a/app/src/main/java/com/kernelmaft/zanbur/common/app-state.kt b/app/src/main/java/com/kernelmaft/zanbur/common/app-state.kt
deleted file mode 100644
index 6abdb42..0000000
--- a/app/src/main/java/com/kernelmaft/zanbur/common/app-state.kt
+++ /dev/null
@@ -1,31 +0,0 @@
-package com.kernelmaft.zanbur.common
-
-
-
-enum class ChangeSource { Local , Remote }
-
-typealias CurrentSceneSubscriber = ( Group , Scene , ChangeSource ) -> Unit
-typealias GroupAddedSubscriber = ( Group , ChangeSource ) -> Unit
-
-object AppState {
-	private val currentSceneSubscribers : MutableList <CurrentSceneSubscriber> = mutableListOf ()
-	private val groupAddedSubscribers : MutableList <GroupAddedSubscriber> = mutableListOf ()
-
-	fun setCurrentScene ( group : Group , newScene : Scene , source : ChangeSource ) {
-		for ( subscriber in currentSceneSubscribers ) {
-			subscriber ( group , newScene , source )
-		}
-	}
-	fun subscribeToCurrentScene ( subscriber : CurrentSceneSubscriber ) {
-		currentSceneSubscribers . add (subscriber)
-	}
-
-	fun addGroup ( newGroup : Group , source : ChangeSource ) {
-		for ( subscriber in groupAddedSubscribers ) {
-			subscriber ( newGroup , source )
-		}
-	}
-	fun subscribeToGroupAdded ( subscriber : GroupAddedSubscriber ) {
-		groupAddedSubscribers . add (subscriber)
-	}
-}
diff --git a/app/src/main/java/com/kernelmaft/zanbur/ui/components.kt b/app/src/main/java/com/kernelmaft/zanbur/components.kt
similarity index 94%
rename from app/src/main/java/com/kernelmaft/zanbur/ui/components.kt
rename to app/src/main/java/com/kernelmaft/zanbur/components.kt
index 03fc6ac..e2d54e9 100644
--- a/app/src/main/java/com/kernelmaft/zanbur/ui/components.kt
+++ b/app/src/main/java/com/kernelmaft/zanbur/components.kt
@@ -1,4 +1,4 @@
-package com.kernelmaft.zanbur.ui
+package com.kernelmaft.zanbur
 
 import androidx.compose.foundation.layout.*
 import androidx.compose.foundation.layout.Arrangement.Center
@@ -9,7 +9,6 @@ import androidx.compose.material3.ButtonDefaults.shape
 import androidx.compose.runtime.*
 import androidx.compose.ui.*
 import androidx.compose.ui.Alignment.Companion.CenterHorizontally
-import com.kernelmaft.zanbur.common.*
 
 
 
diff --git a/app/src/main/java/com/kernelmaft/zanbur/common/config.kt b/app/src/main/java/com/kernelmaft/zanbur/config.kt
similarity index 92%
rename from app/src/main/java/com/kernelmaft/zanbur/common/config.kt
rename to app/src/main/java/com/kernelmaft/zanbur/config.kt
index 3e4ddda..ef1f384 100644
--- a/app/src/main/java/com/kernelmaft/zanbur/common/config.kt
+++ b/app/src/main/java/com/kernelmaft/zanbur/config.kt
@@ -1,4 +1,4 @@
-package com.kernelmaft.zanbur.common
+package com.kernelmaft.zanbur
 
 
 
diff --git a/app/src/main/java/com/kernelmaft/zanbur/main.kt b/app/src/main/java/com/kernelmaft/zanbur/main.kt
new file mode 100644
index 0000000..769890f
--- /dev/null
+++ b/app/src/main/java/com/kernelmaft/zanbur/main.kt
@@ -0,0 +1,65 @@
+package com.kernelmaft.zanbur
+
+import android.os.*
+import androidx.activity.compose.*
+import androidx.compose.foundation.layout.*
+import androidx.compose.runtime.*
+import androidx.compose.ui.*
+import androidx.compose.ui.unit.*
+import androidx.datastore.preferences.core.*
+import androidx.lifecycle.*
+import kotlinx.coroutines.*
+import kotlinx.coroutines.Dispatchers.IO
+import kotlinx.coroutines.flow.*
+
+
+
+class MainActivity : EdgeToEdgeActivity () {
+	override fun onCreate ( savedInstanceState : Bundle ? ) {
+		super . onCreate (savedInstanceState)
+
+		Config . groups . forEach { AppState . addGroup (it) }
+
+		var groups by mutableStateOf ( AppState . groups )
+		AppState . subscribe { groups = it }
+
+		lifecycleScope . launch (IO) {
+			val prefs = dataStore . data . firstOrNull ()
+			if ( prefs != null ) {
+				val savedSceneName = prefs [ stringPreferencesKey ("scene") ]
+				if ( savedSceneName != null ) {
+					val savedScene = AppState . groups [0] . scenes . find { it . name == savedSceneName }
+					if ( savedScene != null ) {
+						AppState . setCurrentScene ( 0 , savedScene )
+					}
+				}
+			}
+		}
+
+		setContent {
+			AppFrame {
+				Column ( Modifier . width ( 300 . dp ) ) {
+					groups . forEach { group ->
+						SceneSwitcher (group) {
+							AppState . setCurrentScene ( group . id , it )
+							publishSceneChange ( group , it )
+						}
+					}
+				}
+			}
+		}
+
+		MqttClient . run (lifecycleScope)
+	}
+
+	override fun onStop () {
+		super . onStop ()
+
+		val currentScene = AppState . groups [0] . currentScene
+		if ( currentScene != null ) lifecycleScope . launch (IO) {
+			applicationContext . dataStore . edit {
+				it [ stringPreferencesKey ("scene") ] = currentScene . name
+			}
+		}
+	}
+}
diff --git a/app/src/main/java/com/kernelmaft/zanbur/network/mqtt.kt b/app/src/main/java/com/kernelmaft/zanbur/mqtt.kt
similarity index 70%
rename from app/src/main/java/com/kernelmaft/zanbur/network/mqtt.kt
rename to app/src/main/java/com/kernelmaft/zanbur/mqtt.kt
index 212d73a..5d633ac 100644
--- a/app/src/main/java/com/kernelmaft/zanbur/network/mqtt.kt
+++ b/app/src/main/java/com/kernelmaft/zanbur/mqtt.kt
@@ -1,16 +1,16 @@
-package com.kernelmaft.zanbur.network
+package com.kernelmaft.zanbur
 
-import com.kernelmaft.zanbur.common.Config.MQTT_SERVER_HOST
-import com.kernelmaft.zanbur.common.Config.MQTT_SERVER_PORT
-import com.kernelmaft.zanbur.common.Config.MQTT_TOPIC
-import io.github.davidepianca98.*
-import io.github.davidepianca98.mqtt.*
-import io.github.davidepianca98.mqtt.MQTTVersion.*
-import io.github.davidepianca98.mqtt.packets.Qos.*
-import io.github.davidepianca98.mqtt.packets.mqtt.*
+import MQTTClient
+import com.kernelmaft.zanbur.Config.MQTT_SERVER_HOST
+import com.kernelmaft.zanbur.Config.MQTT_SERVER_PORT
+import com.kernelmaft.zanbur.Config.MQTT_TOPIC
 import kotlinx.coroutines.*
 import kotlinx.coroutines.Dispatchers.IO
 import kotlinx.serialization.json.*
+import mqtt.*
+import mqtt.MQTTVersion.*
+import mqtt.packets.Qos.*
+import mqtt.packets.mqtt.*
 
 
 
diff --git a/app/src/main/java/com/kernelmaft/zanbur/common/ontology.kt b/app/src/main/java/com/kernelmaft/zanbur/ontology.kt
similarity index 83%
rename from app/src/main/java/com/kernelmaft/zanbur/common/ontology.kt
rename to app/src/main/java/com/kernelmaft/zanbur/ontology.kt
index 86e8a1c..4bec33e 100644
--- a/app/src/main/java/com/kernelmaft/zanbur/common/ontology.kt
+++ b/app/src/main/java/com/kernelmaft/zanbur/ontology.kt
@@ -1,4 +1,4 @@
-package com.kernelmaft.zanbur.common
+package com.kernelmaft.zanbur
 
 
 
diff --git a/app/src/main/java/com/kernelmaft/zanbur/persistence.kt b/app/src/main/java/com/kernelmaft/zanbur/persistence.kt
new file mode 100644
index 0000000..9110f71
--- /dev/null
+++ b/app/src/main/java/com/kernelmaft/zanbur/persistence.kt
@@ -0,0 +1,10 @@
+package com.kernelmaft.zanbur
+
+import android.content.*
+import androidx.datastore.core.*
+import androidx.datastore.preferences.*
+import androidx.datastore.preferences.core.*
+
+
+
+val Context . dataStore : DataStore <Preferences> by preferencesDataStore ("state")
diff --git a/app/src/main/java/com/kernelmaft/zanbur/ui/theme.kt b/app/src/main/java/com/kernelmaft/zanbur/theme.kt
similarity index 94%
rename from app/src/main/java/com/kernelmaft/zanbur/ui/theme.kt
rename to app/src/main/java/com/kernelmaft/zanbur/theme.kt
index 0da4c53..8a95cbc 100644
--- a/app/src/main/java/com/kernelmaft/zanbur/ui/theme.kt
+++ b/app/src/main/java/com/kernelmaft/zanbur/theme.kt
@@ -1,4 +1,4 @@
-package com.kernelmaft.zanbur.ui
+package com.kernelmaft.zanbur
 
 import android.os.*
 import androidx.activity.*
@@ -29,6 +29,7 @@ open class EdgeToEdgeActivity : ComponentActivity () {
 	override fun onCreate ( savedInstanceState : Bundle ? ) {
 		super . onCreate (savedInstanceState)
 
+		enableEdgeToEdge ()
 		actionBar ?. hide ()
 	}
 }
diff --git a/app/src/main/java/com/kernelmaft/zanbur/ui/compose-state.kt b/app/src/main/java/com/kernelmaft/zanbur/ui/compose-state.kt
deleted file mode 100644
index 212f254..0000000
--- a/app/src/main/java/com/kernelmaft/zanbur/ui/compose-state.kt
+++ /dev/null
@@ -1,22 +0,0 @@
-package com.kernelmaft.zanbur.ui
-
-import androidx.compose.runtime.*
-import com.kernelmaft.zanbur.common.*
-
-
-
-fun createGroupsComposeState () : MutableState < List <Group> > {
-	val groups : MutableState < List <Group> > = mutableStateOf ( emptyList () )
-
-	AppState . subscribeToGroupAdded { newGroup , _ ->
-		groups . value = groups . value . plus (newGroup)
-	}
-	AppState . subscribeToCurrentScene { group , newScene , source ->
-		groups . value = groups . value . map { when ( it . id ) {
-			group . id -> it . copy ( currentScene = newScene )
-			else -> it
-		} }
-	}
-
-	return groups
-}
diff --git a/app/src/main/java/com/kernelmaft/zanbur/ui/main-activity.kt b/app/src/main/java/com/kernelmaft/zanbur/ui/main-activity.kt
deleted file mode 100644
index 147fd0c..0000000
--- a/app/src/main/java/com/kernelmaft/zanbur/ui/main-activity.kt
+++ /dev/null
@@ -1,43 +0,0 @@
-package com.kernelmaft.zanbur.ui
-
-import android.os.*
-import androidx.activity.compose.*
-import androidx.compose.foundation.layout.*
-import androidx.compose.ui.*
-import androidx.compose.ui.unit.*
-import androidx.lifecycle.*
-import com.kernelmaft.zanbur.common.*
-import com.kernelmaft.zanbur.common.ChangeSource.*
-import com.kernelmaft.zanbur.network.*
-
-
-
-class MainActivity : EdgeToEdgeActivity () {
-	override fun onCreate ( savedInstanceState : Bundle ? ) {
-		super . onCreate (savedInstanceState)
-
-		val groups = createGroupsComposeState ()
-
-		AppState . subscribeToCurrentScene { group , newScene , source ->
-			if ( source == Local ) {
-				publishSceneChange ( group , newScene )
-			}
-		}
-
-		Config . groups . forEach { AppState . addGroup ( it , Remote ) }
-
-		setContent {
-			AppFrame {
-				Column ( Modifier . width ( 300 . dp ) ) {
-					groups . value . forEach { group ->
-						SceneSwitcher (group) { newScene ->
-							AppState . setCurrentScene ( group , newScene , Local )
-						}
-					}
-				}
-			}
-		}
-
-		MqttClient . run (lifecycleScope)
-	}
-}
diff --git a/app/src/main/java/com/kernelmaft/zanbur/network/zigbee2mqtt.kt b/app/src/main/java/com/kernelmaft/zanbur/zigbee2mqtt.kt
similarity index 77%
rename from app/src/main/java/com/kernelmaft/zanbur/network/zigbee2mqtt.kt
rename to app/src/main/java/com/kernelmaft/zanbur/zigbee2mqtt.kt
index e59269f..0dc2d88 100644
--- a/app/src/main/java/com/kernelmaft/zanbur/network/zigbee2mqtt.kt
+++ b/app/src/main/java/com/kernelmaft/zanbur/zigbee2mqtt.kt
@@ -1,7 +1,6 @@
-package com.kernelmaft.zanbur.network
+package com.kernelmaft.zanbur
 
-import com.kernelmaft.zanbur.common.*
-import com.kernelmaft.zanbur.common.Config.MQTT_TOPIC
+import com.kernelmaft.zanbur.Config.MQTT_TOPIC
 import kotlinx.serialization.*
 import kotlinx.serialization.json.*
 
diff --git a/app/src/main/res/values/strings.xml b/app/src/main/res/values/strings.xml
new file mode 100644
index 0000000..30feaa0
--- /dev/null
+++ b/app/src/main/res/values/strings.xml
@@ -0,0 +1,6 @@
+<resources>
+
+	<string name = "app_name" >Zanbur</string>
+	<string name = "title_activity_main" >Zanbur</string>
+
+</resources>
diff --git a/app/src/main/res/values/themes.xml b/app/src/main/res/values/themes.xml
new file mode 100644
index 0000000..ced7955
--- /dev/null
+++ b/app/src/main/res/values/themes.xml
@@ -0,0 +1,8 @@
+<resources>
+
+	<style
+		name = "Theme.Zanbur"
+		parent = "Theme.Material3.DayNight" >
+	</style>
+
+</resources>