diff --git a/LeCountdown.xcodeproj/project.pbxproj b/LeCountdown.xcodeproj/project.pbxproj
index f56161f..46b93df 100644
--- a/LeCountdown.xcodeproj/project.pbxproj
+++ b/LeCountdown.xcodeproj/project.pbxproj
@@ -114,6 +114,9 @@
 		C4742B59298411E800D5D950 /* CountdownFormView.swift in Sources */ = {isa = PBXBuildFile; fileRef = C4742B58298411E800D5D950 /* CountdownFormView.swift */; };
 		C4742B5B298414B000D5D950 /* ImageSelectionView.swift in Sources */ = {isa = PBXBuildFile; fileRef = C4742B5A298414B000D5D950 /* ImageSelectionView.swift */; };
 		C4742B5F2984205000D5D950 /* ViewModifiers.swift in Sources */ = {isa = PBXBuildFile; fileRef = C4742B5E2984205000D5D950 /* ViewModifiers.swift */; };
+		C47C933529F01B5E00C780E2 /* FileLogger.swift in Sources */ = {isa = PBXBuildFile; fileRef = C4556F6A29E40B7800DEB40B /* FileLogger.swift */; };
+		C47C933629F01B6600C780E2 /* FileUtils.swift in Sources */ = {isa = PBXBuildFile; fileRef = C4556F6E29E40BED00DEB40B /* FileUtils.swift */; };
+		C47C933729F01B7A00C780E2 /* Codable+Extensions.swift in Sources */ = {isa = PBXBuildFile; fileRef = C4556F7029E40DCF00DEB40B /* Codable+Extensions.swift */; };
 		C48ECC0829DAC45900DE5A66 /* AppGuard.swift in Sources */ = {isa = PBXBuildFile; fileRef = C4BA2B56299FFA4F00CB4FBA /* AppGuard.swift */; };
 		C48ECC0929DAC47200DE5A66 /* AppGuard.swift in Sources */ = {isa = PBXBuildFile; fileRef = C4BA2B56299FFA4F00CB4FBA /* AppGuard.swift */; };
 		C498E59F298D4DEA00E90DE0 /* LiveTimerListView.swift in Sources */ = {isa = PBXBuildFile; fileRef = C498E59E298D4DEA00E90DE0 /* LiveTimerListView.swift */; };
@@ -1349,6 +1352,7 @@
 				C498E5A6299152C600E90DE0 /* GreenCheckmarkView.swift in Sources */,
 				C4BA2B3B299F838000CB4FBA /* Model+SharedExtensions.swift in Sources */,
 				C438C7EB2981266F00BF3EF9 /* SingleTimerView.swift in Sources */,
+				C47C933729F01B7A00C780E2 /* Codable+Extensions.swift in Sources */,
 				C438C7D62981216200BF3EF9 /* LaunchWidgetBundle.swift in Sources */,
 				C4BA2B16299BE6A000CB4FBA /* IntervalGroup+CoreDataClass.swift in Sources */,
 				C4F8B18B298AC288005C86A5 /* Record+CoreDataClass.swift in Sources */,
@@ -1358,6 +1362,7 @@
 				C4BA2AF72996A4EF00CB4FBA /* CustomSound+CoreDataClass.swift in Sources */,
 				C4F8B1AD298AC451005C86A5 /* AbstractSoundTimer+CoreDataClass.swift in Sources */,
 				C445FA87298448730054D761 /* CoolPic.swift in Sources */,
+				C47C933529F01B5E00C780E2 /* FileLogger.swift in Sources */,
 				C438C8162982BE1E00BF3EF9 /* LeCountdown.xcdatamodeld in Sources */,
 				C4BA2B4A299FCE0C00CB4FBA /* IntervalGroup+CoreDataProperties.swift in Sources */,
 				C4BA2B4D299FCE0C00CB4FBA /* Stopwatch+CoreDataProperties.swift in Sources */,
@@ -1376,6 +1381,7 @@
 				C438C7DA2981216200BF3EF9 /* LaunchWidget.swift in Sources */,
 				C4BA2AF62996A4EF00CB4FBA /* CustomSound+CoreDataProperties.swift in Sources */,
 				C4F8B192298AC288005C86A5 /* Activity+CoreDataProperties.swift in Sources */,
+				C47C933629F01B6600C780E2 /* FileUtils.swift in Sources */,
 				C4BA2B18299BE6A000CB4FBA /* Interval+CoreDataClass.swift in Sources */,
 				C4F8B18E298AC288005C86A5 /* AbstractTimer+CoreDataProperties.swift in Sources */,
 				C4A16DC829D311C800143D5E /* Extensions.swift in Sources */,
diff --git a/LeCountdown.xcodeproj/xcshareddata/xcschemes/LeCountdown.xcscheme b/LeCountdown.xcodeproj/xcshareddata/xcschemes/LeCountdown.xcscheme
index 7113a0f..22e466d 100644
--- a/LeCountdown.xcodeproj/xcshareddata/xcschemes/LeCountdown.xcscheme
+++ b/LeCountdown.xcodeproj/xcshareddata/xcschemes/LeCountdown.xcscheme
@@ -64,13 +64,6 @@
             isEnabled = "YES">
          </CommandLineArgument>
       </CommandLineArguments>
-      <AdditionalOptions>
-         <AdditionalOption
-            key = "NSZombieEnabled"
-            value = "YES"
-            isEnabled = "YES">
-         </AdditionalOption>
-      </AdditionalOptions>
    </LaunchAction>
    <ProfileAction
       buildConfiguration = "Release"
diff --git a/LeCountdown/AppDelegate.swift b/LeCountdown/AppDelegate.swift
index 251b142..15e10ee 100644
--- a/LeCountdown/AppDelegate.swift
+++ b/LeCountdown/AppDelegate.swift
@@ -27,7 +27,7 @@ class AppDelegate : NSObject, UIApplicationDelegate {
         UNUserNotificationCenter.current().delegate = self
         
         self._initSchemaIfNeeded()
-        self._activateAudioSession()
+//        self._activateAudioSession()
         
         Sound.computeSoundDurationsIfNecessary()
 
@@ -40,6 +40,10 @@ class AppDelegate : NSObject, UIApplicationDelegate {
         return true
     }
     
+    func applicationWillEnterForeground(_ application: UIApplication) {
+        self._activateAudioSession()
+    }
+    
     func applicationWillTerminate(_ application: UIApplication) {
         Logger.log("applicationWillTerminate")
         FileLogger.log("applicationWillTerminate")
@@ -63,6 +67,7 @@ class AppDelegate : NSObject, UIApplicationDelegate {
     }
     
     fileprivate func _activateAudioSession() {
+        Logger.log("_activateAudioSession")
         do {
             let audioSession: AVAudioSession = AVAudioSession.sharedInstance()
             try audioSession.setCategory(.playback, options: .duckOthers)
@@ -114,6 +119,7 @@ extension AppDelegate: UNUserNotificationCenterDelegate {
         if components.count == 2 {
             return components[0]
         } else {
+            FileLogger.log("app terminated by ourselves")
             fatalError("bad notification format : \(notificationId)")
         }
     }
diff --git a/LeCountdown/Conductor.swift b/LeCountdown/Conductor.swift
index a550f3c..8acedb9 100644
--- a/LeCountdown/Conductor.swift
+++ b/LeCountdown/Conductor.swift
@@ -69,7 +69,7 @@ class Conductor: ObservableObject {
         self.currentStopwatches.removeValue(forKey: id)
         self.cancelledCountdowns.removeAll(where: { $0 == id })
         if let soundPlayer = self._delayedSoundPlayers[id] {
-            FileLogger.log("Stop sound player: \(id)")
+            FileLogger.log("Stop sound player: \(self._timerName(id))")
             soundPlayer.stop()
         }
     }
@@ -80,8 +80,6 @@ class Conductor: ObservableObject {
     
     fileprivate func _buildLiveTimers() {
         
-//        Logger.log("_buildLiveTimers")
-        
         let liveCountdowns = self.currentCountdowns.map {
             return LiveTimer(id: $0, date: $1.end)
         }
@@ -144,7 +142,7 @@ class Conductor: ObservableObject {
             do {
                 let start = Date()
                 let end = start.addingTimeInterval(countdown.duration)
-                FileLogger.log("schedule countdown \(countdownId) at \(end)")
+                FileLogger.log("schedule countdown \(self._timerName(countdownId)) at \(end)")
                 
                 let sound = countdown.someSound
                 let soundPlayer = try DelaySoundPlayer(timerID: countdownId, sound: sound)
@@ -183,7 +181,7 @@ class Conductor: ObservableObject {
     
     func cancelCountdown(id: TimerID) {
         
-        FileLogger.log("Cancel \(id)")
+        FileLogger.log("Cancel \(self._timerName(id))")
         CountdownScheduler.master.cancelCurrentNotifications(countdownId: id)
         self.cancelSoundPlayer(id: id)
         self.cancelledCountdowns.append(id)
@@ -256,7 +254,7 @@ class Conductor: ObservableObject {
                         let sound: Sound = countdown.someSound
                         let soundPlayer = try DelaySoundPlayer(timerID: countdownId, sound: sound)
                         self._delayedSoundPlayers[countdown.stringId] = soundPlayer
-                        FileLogger.log("Restored sound player for \(countdown.stringId)")
+                        FileLogger.log("Restored sound player for \(self._timerName(countdownId))")
                         try soundPlayer.restore(for: interval.end, repeatCount: Int(countdown.repeatCount))
                     } catch {
                         Logger.error(error)
@@ -357,7 +355,7 @@ class Conductor: ObservableObject {
         if let soundPlayer = self._delayedSoundPlayers[id] {
             soundPlayer.stop()
             self._delayedSoundPlayers.removeValue(forKey: id)
-            FileLogger.log("cancelled sound player for \(id)")
+            FileLogger.log("cancelled sound player for \(self._timerName(id))")
         }
         
         self.deactivateAudioSessionIfPossible()
@@ -457,4 +455,8 @@ class Conductor: ObservableObject {
         }
     }
 
+    fileprivate func _timerName(_ id: TimerID) -> String {
+        return IntentDataProvider.main.timer(id: id)?.name ?? id
+    }
+    
 }
diff --git a/LeCountdown/Model/Model+SharedExtensions.swift b/LeCountdown/Model/Model+SharedExtensions.swift
index 6fcc332..dfbf649 100644
--- a/LeCountdown/Model/Model+SharedExtensions.swift
+++ b/LeCountdown/Model/Model+SharedExtensions.swift
@@ -27,6 +27,7 @@ extension AbstractTimer {
         if let url = URL(string: self.stringId) {
             return url
         } else {
+//            FileLogger.log("app terminated by ourselves")
             fatalError("Can't produce url with \(self.stringId)")
         }
     }
diff --git a/LeCountdown/Model/Persistence.swift b/LeCountdown/Model/Persistence.swift
index 7756d3f..fa6c830 100644
--- a/LeCountdown/Model/Persistence.swift
+++ b/LeCountdown/Model/Persistence.swift
@@ -53,6 +53,7 @@ struct PersistenceController {
             // Replace this implementation with code to handle the error appropriately.
             // fatalError() causes the application to generate a crash log and terminate. You should not use this function in a shipping application, although it may be useful during development.
             let nsError = error as NSError
+            FileLogger.log("app terminated by ourselves")
             fatalError("Unresolved error \(nsError), \(nsError.userInfo)")
         }
         return result
@@ -101,6 +102,7 @@ struct PersistenceController {
                  * The store could not be migrated to the current model version.
                  Check the error message to determine what the actual problem was.
                  */
+                FileLogger.log("app terminated by ourselves")
                 fatalError("Unresolved error \(error), \(error.userInfo)")
             }
         })
@@ -114,6 +116,7 @@ fileprivate extension URL {
     /// Returns a URL for the given app group and database pointing to the sqlite database.
     static func storeURL(for appGroup: String, databaseName: String) -> URL {
         guard let fileContainer = FileManager.default.containerURL(forSecurityApplicationGroupIdentifier: appGroup) else {
+            FileLogger.log("app terminated by ourselves")
             fatalError("Shared file container could not be created.")
         }
 
diff --git a/LeCountdown/Sound/DelaySoundPlayer.swift b/LeCountdown/Sound/DelaySoundPlayer.swift
index 2bd013d..15dd023 100644
--- a/LeCountdown/Sound/DelaySoundPlayer.swift
+++ b/LeCountdown/Sound/DelaySoundPlayer.swift
@@ -46,8 +46,8 @@ import AVFoundation
         
         Logger.log("self._player.deviceCurrentTime = \(self._player.deviceCurrentTime)")
         let time: TimeInterval = self._player.deviceCurrentTime + duration
-        self._player.play(atTime: time)
-        FileLogger.log("self._player.play(atTime: \(time)")
+        let result = self._player.play(atTime: time)
+        FileLogger.log("play \(String(describing: self._player.url)) >atTime: \(time), result = \(result), isMainThread = \(Thread.isMainThread)")
     }
     
     func stop() {
@@ -58,10 +58,9 @@ import AVFoundation
     // MARK: - Delegate
 
     func audioPlayerDidFinishPlaying(_ player: AVAudioPlayer, successfully flag: Bool) {
-        FileLogger.log("audioPlayerDidFinishPlaying: successfully = \(flag)")
-
+        FileLogger.log("audioPlayerDidFinishPlaying: successfully = \(flag), player volume = \(player.volume)")
+        
         Logger.log("audioPlayerDidFinishPlaying: successfully = \(flag)")
-//        Conductor.maestro.cancelSoundPlayer(id: self._timerID)
         Conductor.maestro.cleanupLiveActivities()
         
         self.stop()
diff --git a/LeCountdown/Utils/TextToSpeechRecorder.swift b/LeCountdown/Utils/TextToSpeechRecorder.swift
index e9a0d23..6862c01 100644
--- a/LeCountdown/Utils/TextToSpeechRecorder.swift
+++ b/LeCountdown/Utils/TextToSpeechRecorder.swift
@@ -27,6 +27,7 @@ class TextToSpeechRecorder {
         
         synthesizer.write(utterance) { buffer in
             guard let pcmBuffer = buffer as? AVAudioPCMBuffer else {
+                FileLogger.log("app terminated by ourselves")
                 fatalError("unknown buffer type: \(buffer)")
             }
             let fileName = "\(UUID().uuidString).caf"