diff --git a/test/mock/audio_provider_mock.dart b/test/mock/audio_provider_mock.dart
new file mode 100644
index 0000000..0a723b4
--- /dev/null
+++ b/test/mock/audio_provider_mock.dart
@@ -0,0 +1,22 @@
+import 'package:audioplayers/audioplayers.dart';
+import 'package:smoke_cess_app/providers/audio_provider.dart';
+
+class AudioProviderMock extends AudioProvider {
+  @override
+  bool get isMuted => true;
+
+  @override
+  void stop() {}
+
+  @override
+  void playFinishSound() {}
+
+  @override
+  void mutePlayer() {}
+
+  @override
+  void unMutePlayer() {}
+
+  @override
+  void playSourceAfterBeep(AssetSource source) {}
+}
diff --git a/test/unit_tests/workout_provider_test.dart b/test/unit_tests/workout_provider_test.dart
index 45c7685..f708703 100644
--- a/test/unit_tests/workout_provider_test.dart
+++ b/test/unit_tests/workout_provider_test.dart
@@ -4,6 +4,7 @@ import 'package:smoke_cess_app/providers/audio_provider.dart';
 import 'package:smoke_cess_app/providers/timer_provider.dart';
 import 'package:smoke_cess_app/providers/workout_provider.dart';
 import 'package:smoke_cess_app/globals.dart' as globals;
+import '../mock/audio_provider_mock.dart';
 import '../mock/db_mock.dart';
 
 void main() {
@@ -16,7 +17,7 @@ void main() {
 
     setUp(() {
       timerProvider = TimerProvider();
-      audioProvider = AudioProvider();
+      audioProvider = AudioProviderMock();
       workoutProvider = WorkoutProvider(timerProvider, audioProvider);
     });
 
diff --git a/test/widget_tests/mute_button_test.dart b/test/widget_tests/mute_button_test.dart
new file mode 100644
index 0000000..bd9d7fe
--- /dev/null
+++ b/test/widget_tests/mute_button_test.dart
@@ -0,0 +1,34 @@
+import 'package:flutter/material.dart';
+import 'package:flutter_test/flutter_test.dart';
+import 'package:provider/provider.dart';
+import 'package:smoke_cess_app/providers/audio_provider.dart';
+import 'package:smoke_cess_app/widgets/buttons/mute_button.dart';
+
+void main() {
+  group('MuteButton', () {
+    testWidgets('should handle mute logic', (WidgetTester tester) async {
+      AudioProvider audioProvider = AudioProvider();
+      await tester.pumpWidget(
+        MaterialApp(
+            home: Scaffold(
+                body: ChangeNotifierProvider(
+                    create: (context) => audioProvider,
+                    child: const MuteButton()))),
+      );
+      final button = find.byType(IconButton);
+      final mutedIcon = find.byIcon(Icons.volume_off_outlined);
+      final unMutedIcon = find.byIcon(Icons.volume_up_outlined);
+      expect(audioProvider.isMuted, false);
+      expect(button, findsOneWidget);
+      expect(mutedIcon, findsNothing);
+      expect(unMutedIcon, findsOneWidget);
+
+      await tester.tap(unMutedIcon);
+      await tester.pump();
+
+      expect(audioProvider.isMuted, true);
+      expect(mutedIcon, findsOneWidget);
+      expect(unMutedIcon, findsNothing);
+    });
+  });
+}
diff --git a/test/widget_tests/timer_widget_test.dart b/test/widget_tests/timer_widget_test.dart
new file mode 100644
index 0000000..9275262
--- /dev/null
+++ b/test/widget_tests/timer_widget_test.dart
@@ -0,0 +1,32 @@
+import 'dart:async';
+
+import 'package:flutter/material.dart';
+import 'package:flutter_test/flutter_test.dart';
+import 'package:provider/provider.dart';
+import 'package:smoke_cess_app/providers/timer_provider.dart';
+import 'package:smoke_cess_app/utils/timer_util.dart';
+import 'package:smoke_cess_app/widgets/timer_widget.dart';
+
+void main() {
+  group('TimerWidget', () {
+    testWidgets('should display duration', (WidgetTester tester) async {
+      TimerProvider timerProvider = TimerProvider();
+      Duration duration = const Duration(minutes: 1);
+      await tester.pumpWidget(
+        MaterialApp(
+            home: Scaffold(
+                body: ChangeNotifierProvider(
+                    create: (context) => timerProvider,
+                    child: TimerWidget(duration: duration)))),
+      );
+
+      final durationTextFinder = find.text(formatTime(duration.inSeconds));
+      expect(durationTextFinder, findsOneWidget);
+
+      timerProvider.startTimer(duration);
+      await tester.pump(const Duration(seconds: 1));
+      expect(durationTextFinder, findsNothing);
+      expect(find.text(formatTime(duration.inSeconds - 1)), findsOneWidget);
+    });
+  });
+}
diff --git a/test/widget_tests/widget_entry_detail_test.dart b/test/widget_tests/widget_entry_detail_test.dart
index 0eed669..a2d3f5a 100644
--- a/test/widget_tests/widget_entry_detail_test.dart
+++ b/test/widget_tests/widget_entry_detail_test.dart
@@ -5,37 +5,39 @@ import 'package:smoke_cess_app/widgets/entry_detail_widget.dart';
 
 void main() {
   initializeDateFormatting('de');
-  testWidgets('Entry Detail should use ExpansionTile if Comments is set',
-      (WidgetTester tester) async {
-    await tester.pumpWidget(
-      MaterialApp(
-          home: Scaffold(
-        body: EntryDetail(
-          date: DateTime.now(),
-          entryComment: 'A comment',
-          entryData: 'Test',
-          iconData: Icons.plus_one,
-        ),
-      )),
-    );
+  group('EntryDetail', () {
+    testWidgets('should use ExpansionTile if Comments is set',
+        (WidgetTester tester) async {
+      await tester.pumpWidget(
+        MaterialApp(
+            home: Scaffold(
+          body: EntryDetail(
+            date: DateTime.now(),
+            entryComment: 'A comment',
+            entryData: 'Test',
+            iconData: Icons.plus_one,
+          ),
+        )),
+      );
 
-    expect(find.byType(ExpansionTile), findsOneWidget);
-  });
+      expect(find.byType(ExpansionTile), findsOneWidget);
+    });
 
-  testWidgets('Entry Detail should use ListTile if Comments is null',
-      (WidgetTester tester) async {
-    await tester.pumpWidget(
-      MaterialApp(
-          home: Scaffold(
-        body: EntryDetail(
-          date: DateTime.now(),
-          entryComment: 'A comment',
-          entryData: 'Test',
-          iconData: Icons.plus_one,
-        ),
-      )),
-    );
+    testWidgets('should use ListTile if Comments is null',
+        (WidgetTester tester) async {
+      await tester.pumpWidget(
+        MaterialApp(
+            home: Scaffold(
+          body: EntryDetail(
+            date: DateTime.now(),
+            entryComment: 'A comment',
+            entryData: 'Test',
+            iconData: Icons.plus_one,
+          ),
+        )),
+      );
 
-    expect(find.byType(ListTile), findsOneWidget);
+      expect(find.byType(ListTile), findsOneWidget);
+    });
   });
 }