diff --git a/.gitignore b/.gitignore
index c6cbe56..5f94008 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1,8 +1,7 @@
 *.iml
 .gradle
 /local.properties
-/.idea/workspace.xml
-/.idea/libraries
+/.idea
 .DS_Store
 /build
 /captures
diff --git a/.idea/codeStyles/Project.xml b/.idea/codeStyles/Project.xml
deleted file mode 100644
index 0c51a83..0000000
--- a/.idea/codeStyles/Project.xml
+++ /dev/null
@@ -1,137 +0,0 @@
-<component name="ProjectCodeStyleConfiguration">
-  <code_scheme name="Project" version="173">
-    <DBN-PSQL>
-      <case-options enabled="false">
-        <option name="KEYWORD_CASE" value="lower" />
-        <option name="FUNCTION_CASE" value="lower" />
-        <option name="PARAMETER_CASE" value="lower" />
-        <option name="DATATYPE_CASE" value="lower" />
-        <option name="OBJECT_CASE" value="preserve" />
-      </case-options>
-      <formatting-settings enabled="false" />
-    </DBN-PSQL>
-    <DBN-SQL>
-      <case-options enabled="false">
-        <option name="KEYWORD_CASE" value="lower" />
-        <option name="FUNCTION_CASE" value="lower" />
-        <option name="PARAMETER_CASE" value="lower" />
-        <option name="DATATYPE_CASE" value="lower" />
-        <option name="OBJECT_CASE" value="preserve" />
-      </case-options>
-      <formatting-settings enabled="false">
-        <option name="STATEMENT_SPACING" value="one_line" />
-        <option name="CLAUSE_CHOP_DOWN" value="chop_down_if_statement_long" />
-        <option name="ITERATION_ELEMENTS_WRAPPING" value="chop_down_if_not_single" />
-      </formatting-settings>
-    </DBN-SQL>
-    <codeStyleSettings language="XML">
-      <arrangement>
-        <rules>
-          <section>
-            <rule>
-              <match>
-                <AND>
-                  <NAME>xmlns:android</NAME>
-                  <XML_ATTRIBUTE />
-                  <XML_NAMESPACE>^$</XML_NAMESPACE>
-                </AND>
-              </match>
-            </rule>
-          </section>
-          <section>
-            <rule>
-              <match>
-                <AND>
-                  <NAME>xmlns:.*</NAME>
-                  <XML_ATTRIBUTE />
-                  <XML_NAMESPACE>^$</XML_NAMESPACE>
-                </AND>
-              </match>
-              <order>BY_NAME</order>
-            </rule>
-          </section>
-          <section>
-            <rule>
-              <match>
-                <AND>
-                  <NAME>.*:id</NAME>
-                  <XML_ATTRIBUTE />
-                  <XML_NAMESPACE>http://schemas.android.com/apk/res/android</XML_NAMESPACE>
-                </AND>
-              </match>
-            </rule>
-          </section>
-          <section>
-            <rule>
-              <match>
-                <AND>
-                  <NAME>.*:name</NAME>
-                  <XML_ATTRIBUTE />
-                  <XML_NAMESPACE>http://schemas.android.com/apk/res/android</XML_NAMESPACE>
-                </AND>
-              </match>
-            </rule>
-          </section>
-          <section>
-            <rule>
-              <match>
-                <AND>
-                  <NAME>name</NAME>
-                  <XML_ATTRIBUTE />
-                  <XML_NAMESPACE>^$</XML_NAMESPACE>
-                </AND>
-              </match>
-            </rule>
-          </section>
-          <section>
-            <rule>
-              <match>
-                <AND>
-                  <NAME>style</NAME>
-                  <XML_ATTRIBUTE />
-                  <XML_NAMESPACE>^$</XML_NAMESPACE>
-                </AND>
-              </match>
-            </rule>
-          </section>
-          <section>
-            <rule>
-              <match>
-                <AND>
-                  <NAME>.*</NAME>
-                  <XML_ATTRIBUTE />
-                  <XML_NAMESPACE>^$</XML_NAMESPACE>
-                </AND>
-              </match>
-              <order>BY_NAME</order>
-            </rule>
-          </section>
-          <section>
-            <rule>
-              <match>
-                <AND>
-                  <NAME>.*</NAME>
-                  <XML_ATTRIBUTE />
-                  <XML_NAMESPACE>http://schemas.android.com/apk/res/android</XML_NAMESPACE>
-                </AND>
-              </match>
-              <order>ANDROID_ATTRIBUTE_ORDER</order>
-            </rule>
-          </section>
-          <section>
-            <rule>
-              <match>
-                <AND>
-                  <NAME>.*</NAME>
-                  <XML_ATTRIBUTE />
-                  <XML_NAMESPACE>.*</XML_NAMESPACE>
-                </AND>
-              </match>
-              <order>BY_NAME</order>
-            </rule>
-          </section>
-        </rules>
-      </arrangement>
-    </codeStyleSettings>
-  </code_scheme>
-</component>
\ No newline at end of file
diff --git a/.idea/compiler.xml b/.idea/compiler.xml
deleted file mode 100644
index fb7f4a8..0000000
--- a/.idea/compiler.xml
+++ /dev/null
@@ -1,6 +0,0 @@
-<?xml version="1.0" encoding="UTF-8"?>
-<project version="4">
-  <component name="CompilerConfiguration">
-    <bytecodeTargetLevel target="11" />
-  </component>
-</project>
\ No newline at end of file
diff --git a/.idea/gradle.xml b/.idea/gradle.xml
deleted file mode 100644
index 7d3c403..0000000
--- a/.idea/gradle.xml
+++ /dev/null
@@ -1,21 +0,0 @@
-<?xml version="1.0" encoding="UTF-8"?>
-<project version="4">
-  <component name="GradleMigrationSettings" migrationVersion="1" />
-  <component name="GradleSettings">
-    <option name="linkedExternalProjectsSettings">
-      <GradleProjectSettings>
-        <option name="testRunner" value="GRADLE" />
-        <option name="distributionType" value="DEFAULT_WRAPPED" />
-        <option name="externalProjectPath" value="$PROJECT_DIR$" />
-        <option name="gradleJvm" value="corretto-11" />
-        <option name="modules">
-          <set>
-            <option value="$PROJECT_DIR$" />
-            <option value="$PROJECT_DIR$/app" />
-            <option value="$PROJECT_DIR$/libs/privacy-friendly-backup-api/BackupAPI" />
-          </set>
-        </option>
-      </GradleProjectSettings>
-    </option>
-  </component>
-</project>
\ No newline at end of file
diff --git a/.idea/jarRepositories.xml b/.idea/jarRepositories.xml
deleted file mode 100644
index f2eacce..0000000
--- a/.idea/jarRepositories.xml
+++ /dev/null
@@ -1,40 +0,0 @@
-<?xml version="1.0" encoding="UTF-8"?>
-<project version="4">
-  <component name="RemoteRepositoriesConfiguration">
-    <remote-repository>
-      <option name="id" value="central" />
-      <option name="name" value="Maven Central repository" />
-      <option name="url" value="https://repo1.maven.org/maven2" />
-    </remote-repository>
-    <remote-repository>
-      <option name="id" value="jboss.community" />
-      <option name="name" value="JBoss Community repository" />
-      <option name="url" value="https://repository.jboss.org/nexus/content/repositories/public/" />
-    </remote-repository>
-    <remote-repository>
-      <option name="id" value="BintrayJCenter" />
-      <option name="name" value="BintrayJCenter" />
-      <option name="url" value="https://jcenter.bintray.com/" />
-    </remote-repository>
-    <remote-repository>
-      <option name="id" value="Google" />
-      <option name="name" value="Google" />
-      <option name="url" value="https://dl.google.com/dl/android/maven2/" />
-    </remote-repository>
-    <remote-repository>
-      <option name="id" value="MavenRepo" />
-      <option name="name" value="MavenRepo" />
-      <option name="url" value="https://repo.maven.apache.org/maven2/" />
-    </remote-repository>
-    <remote-repository>
-      <option name="id" value="MavenLocal" />
-      <option name="name" value="MavenLocal" />
-      <option name="url" value="file:$USER_HOME$/.m2/repository" />
-    </remote-repository>
-    <remote-repository>
-      <option name="id" value="MavenLocal" />
-      <option name="name" value="MavenLocal" />
-      <option name="url" value="file:$USER_HOME$/.m2/repository/" />
-    </remote-repository>
-  </component>
-</project>
\ No newline at end of file
diff --git a/.idea/kotlinc.xml b/.idea/kotlinc.xml
deleted file mode 100644
index e1eea1d..0000000
--- a/.idea/kotlinc.xml
+++ /dev/null
@@ -1,6 +0,0 @@
-<?xml version="1.0" encoding="UTF-8"?>
-<project version="4">
-  <component name="KotlinJpsPluginSettings">
-    <option name="version" value="1.7.20" />
-  </component>
-</project>
\ No newline at end of file
diff --git a/.idea/misc.xml b/.idea/misc.xml
deleted file mode 100644
index e9a58ca..0000000
--- a/.idea/misc.xml
+++ /dev/null
@@ -1,4 +0,0 @@
-<project version="4">
-  <component name="ExternalStorageConfigurationManager" enabled="true" />
-  <component name="ProjectRootManager" version="2" languageLevel="JDK_11" default="true" project-jdk-name="corretto-11" project-jdk-type="JavaSDK" />
-</project>
\ No newline at end of file
diff --git a/.idea/vcs.xml b/.idea/vcs.xml
deleted file mode 100644
index 7df27e1..0000000
--- a/.idea/vcs.xml
+++ /dev/null
@@ -1,7 +0,0 @@
-<?xml version="1.0" encoding="UTF-8"?>
-<project version="4">
-  <component name="VcsDirectoryMappings">
-    <mapping directory="" vcs="Git" />
-    <mapping directory="$PROJECT_DIR$/libs/privacy-friendly-backup-api" vcs="Git" />
-  </component>
-</project>
\ No newline at end of file
diff --git a/app/build.gradle b/app/build.gradle
index af10d90..6bdad17 100644
--- a/app/build.gradle
+++ b/app/build.gradle
@@ -3,14 +3,15 @@ apply plugin: 'kotlin-android'
 
 
 android {
-    compileSdkVersion 33
+    compileSdk 34
 
+    namespace 'org.secuso.aktivpause'
     defaultConfig {
         applicationId "org.secuso.aktivpause"
         minSdkVersion 21
-        targetSdkVersion 33
+        targetSdkVersion 34
         versionCode 10
-        versionName "1.2.0"
+        versionName "1.2.1"
         vectorDrawables.useSupportLibrary = true
     }
     buildTypes {
@@ -19,12 +20,21 @@ android {
             proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'
         }
     }
-    compileOptions {
-        sourceCompatibility JavaVersion.VERSION_1_8
-        targetCompatibility JavaVersion.VERSION_1_8
+    buildFeatures {
+        buildConfig true
+    }
+    compileOptions {
+        sourceCompatibility JavaVersion.VERSION_17
+        targetCompatibility JavaVersion.VERSION_17
+    }
+    kotlinOptions {
+        jvmTarget = JavaVersion.VERSION_17.toString()
+    }
+    kotlin {
+        jvmToolchain(17)
     }
-    namespace 'org.secuso.aktivpause'
     lint {
+        lintConfig = file("lint.xml")
         abortOnError false
         checkReleaseBuilds false
     }
@@ -49,7 +59,7 @@ dependencies {
     implementation 'com.readystatesoftware.sqliteasset:sqliteassethelper:2.0.1'
     testImplementation 'junit:junit:4.12'
     // https://github.com/ShawnLin013/NumberPicker
-    implementation 'com.shawnlin:number-picker:2.4.4'
+    implementation 'io.github.ShawnLin013:number-picker:2.4.13'
 
     // Backup
     implementation project(path: ':backup-api')
diff --git a/app/lint.xml b/app/lint.xml
new file mode 100644
index 0000000..1da88bd
--- /dev/null
+++ b/app/lint.xml
@@ -0,0 +1,6 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<lint>
+    <!-- Set the severity of missing translations to warning instead of error -->
+    <issue id="MissingTranslation" severity="warning" />
+    <issue id="MissingQuantity" severity="warning" />
+</lint>
diff --git a/app/src/main/AndroidManifest.xml b/app/src/main/AndroidManifest.xml
index 9707c46..88e8f33 100644
--- a/app/src/main/AndroidManifest.xml
+++ b/app/src/main/AndroidManifest.xml
@@ -11,6 +11,7 @@
     <uses-permission android:name="android.permission.RECEIVE_BOOT_COMPLETED" />
     <uses-permission android:name="android.permission.WAKE_LOCK" />
     <uses-permission android:name="android.permission.FOREGROUND_SERVICE" />
+    <uses-permission android:name="android.permission.FOREGROUND_SERVICE_SPECIAL_USE" />
 
     <application
         android:name=".PFAktivpause"
@@ -119,7 +120,8 @@
         <service
             android:name="org.secuso.aktivpause.service.TimerService"
             android:enabled="true"
-            android:exported="false" />
+            android:exported="false"
+            android:foregroundServiceType="specialUse"/>
         <service
             android:name=".backup.PFABackupService"
             android:enabled="true"
diff --git a/app/src/main/java/org/secuso/aktivpause/PFAktivpause.kt b/app/src/main/java/org/secuso/aktivpause/PFAktivpause.kt
index 05b7dd9..28e489a 100644
--- a/app/src/main/java/org/secuso/aktivpause/PFAktivpause.kt
+++ b/app/src/main/java/org/secuso/aktivpause/PFAktivpause.kt
@@ -15,7 +15,7 @@ class PFAktivpause : Application(), Configuration.Provider {
         BackupManager.backupRestorer = BackupRestorer()
     }
 
-    override fun getWorkManagerConfiguration(): Configuration {
-        return Configuration.Builder().setMinimumLoggingLevel(Log.INFO).build()
+    override val workManagerConfiguration by lazy {
+        Configuration.Builder().setMinimumLoggingLevel(Log.INFO).build()
     }
 }
\ No newline at end of file
diff --git a/app/src/main/java/org/secuso/aktivpause/activities/TimerActivity.java b/app/src/main/java/org/secuso/aktivpause/activities/TimerActivity.java
index 6d28457..0f3c4ce 100644
--- a/app/src/main/java/org/secuso/aktivpause/activities/TimerActivity.java
+++ b/app/src/main/java/org/secuso/aktivpause/activities/TimerActivity.java
@@ -12,7 +12,6 @@ import android.graphics.drawable.Drawable;
 import android.net.Uri;
 import android.os.IBinder;
 import android.preference.PreferenceManager;
-import androidx.annotation.NonNull;
 import androidx.constraintlayout.widget.ConstraintLayout;
 import androidx.constraintlayout.widget.ConstraintSet;
 import androidx.core.app.ActivityCompat;
@@ -117,12 +116,9 @@ public class TimerActivity extends BaseActivity implements LoaderManager.LoaderC
             boolean isRunning = intent.getBooleanExtra("isRunning", false);
             boolean isPaused = intent.getBooleanExtra("isPaused", false);
 
-            //if(intent.getBooleanExtra("done" ,false)) {
-                // TODO: show a dialog here to start the exercise?
-            //}
-
-            //Log.d(TAG, millisUntilDone + "/" + initialDuration + " (" + (isRunning ? "Running" : "") + (isPaused ? "Paused" : "") + (!isRunning && !isPaused ?  "Stopped" : "") + ")");
-
+            if (millisUntilDone <= 0) {
+                startActivity(new Intent(TimerActivity.this, ExerciseActivity.class));
+            }
             updateUI(isRunning, isPaused, initialDuration, millisUntilDone);
         }
     };
diff --git a/app/src/main/java/org/secuso/aktivpause/service/TimerService.java b/app/src/main/java/org/secuso/aktivpause/service/TimerService.java
index f42aa08..8b74948 100644
--- a/app/src/main/java/org/secuso/aktivpause/service/TimerService.java
+++ b/app/src/main/java/org/secuso/aktivpause/service/TimerService.java
@@ -9,12 +9,14 @@ import android.content.Context;
 import android.content.Intent;
 import android.content.IntentFilter;
 import android.content.SharedPreferences;
+import android.content.pm.ServiceInfo;
 import android.os.Binder;
 import android.os.CountDownTimer;
 import android.os.IBinder;
 import android.preference.PreferenceManager;
 import android.provider.Settings;
 import androidx.core.app.NotificationCompat;
+import androidx.core.app.ServiceCompat;
 import androidx.core.content.ContextCompat;
 
 import org.secuso.aktivpause.R;
@@ -33,6 +35,7 @@ import static org.secuso.aktivpause.activities.tutorial.FirstLaunchManager.WORK_
 import static org.secuso.aktivpause.receivers.NotificationCancelReceiver.ACTION_NOTIFICATION_CANCELED;
 import static org.secuso.aktivpause.receivers.NotificationDeletedReceiver.ACTION_NOTIFICATION_DELETED;
 
+import kotlin.Unit;
 /**
  * The main timer service. It handles the work timer and sends updates to the notification and the {@link TimerActivity}.
  * When the work time is up, an alarm will fire to start the exercises.
@@ -139,9 +142,10 @@ public class TimerService extends Service {
     public void onCreate() {
         super.onCreate();
 
+
         registerReceiver(timerReceiver, new IntentFilter(TIMER_BROADCAST));
-        registerReceiver(notificationDeletedReceiver, new IntentFilter(ACTION_NOTIFICATION_DELETED));
-        registerReceiver(notificationPreferenceChangedReceiver, new IntentFilter(ACTION_NOTIFICATION_CANCELED));
+        ContextCompat.registerReceiver(this, notificationDeletedReceiver, new IntentFilter(ACTION_NOTIFICATION_DELETED), ContextCompat.RECEIVER_NOT_EXPORTED);
+        ContextCompat.registerReceiver(this, notificationPreferenceChangedReceiver, new IntentFilter(ACTION_NOTIFICATION_CANCELED),  ContextCompat.RECEIVER_NOT_EXPORTED);
     }
 
     @Override
@@ -363,7 +367,7 @@ public class TimerService extends Service {
 
     private void updateNotification() {
         if(isRunning() || isPaused()) {
-            startForeground(NOTIFICATION_ID, buildNotification());
+            ServiceCompat.startForeground(this, NOTIFICATION_ID, buildNotification(), ServiceInfo.FOREGROUND_SERVICE_TYPE_SPECIAL_USE);
         } else {
             stopForeground(true);
         }
diff --git a/build.gradle b/build.gradle
index 5905cb1..a8e5d0e 100644
--- a/build.gradle
+++ b/build.gradle
@@ -2,7 +2,7 @@
 
 buildscript {
     repositories {
-        jcenter()
+        mavenCentral()
         maven {
             url 'https://maven.google.com/'
             name 'Google'
@@ -10,9 +10,9 @@ buildscript {
         google()
     }
 
-    ext.kotlin_version = "1.7.20"
+    ext.kotlin_version = "2.0.21"
     dependencies {
-        classpath 'com.android.tools.build:gradle:7.4.2'
+        classpath 'com.android.tools.build:gradle:8.3.2'
         classpath "org.jetbrains.kotlin:kotlin-gradle-plugin:$kotlin_version"
 
         // NOTE: Do not place your application dependencies here; they belong
@@ -22,7 +22,7 @@ buildscript {
 
 allprojects {
     repositories {
-        jcenter()
+        mavenCentral()
         google()
     }
 }
diff --git a/gradle.properties b/gradle.properties
index 915f0e6..10c8f5e 100644
--- a/gradle.properties
+++ b/gradle.properties
@@ -16,5 +16,8 @@
 # This option should only be used with decoupled projects. More details, visit
 # http://www.gradle.org/docs/current/userguide/multi_project_builds.html#sec:decoupled_projects
 # org.gradle.parallel=true
+android.defaults.buildfeatures.buildconfig=true
 android.enableJetifier=true
+android.nonFinalResIds=false
+android.nonTransitiveRClass=false
 android.useAndroidX=true
\ No newline at end of file
diff --git a/gradle/wrapper/gradle-wrapper.properties b/gradle/wrapper/gradle-wrapper.properties
index b32f7f6..5047464 100644
--- a/gradle/wrapper/gradle-wrapper.properties
+++ b/gradle/wrapper/gradle-wrapper.properties
@@ -1,6 +1,6 @@
 #Wed May 24 23:28:16 CEST 2023
 distributionBase=GRADLE_USER_HOME
 distributionPath=wrapper/dists
-distributionUrl=https\://services.gradle.org/distributions/gradle-7.5-bin.zip
+distributionUrl=https\://services.gradle.org/distributions/gradle-8.5-bin.zip
 zipStoreBase=GRADLE_USER_HOME
 zipStorePath=wrapper/dists
diff --git a/libs/privacy-friendly-backup-api b/libs/privacy-friendly-backup-api
index d9e4a62..14ee29f 160000
--- a/libs/privacy-friendly-backup-api
+++ b/libs/privacy-friendly-backup-api
@@ -1 +1 @@
-Subproject commit d9e4a62a7c667de2538681c39394c828f8d26a37
+Subproject commit 14ee29f59bc7c3fbaa765cb1be0fcaab4f948b88