diff --git a/app/src/main/java/org/y20k/trackbook/MainActivity.kt b/app/src/main/java/org/y20k/trackbook/MainActivity.kt
index 5f32941..157c11e 100644
--- a/app/src/main/java/org/y20k/trackbook/MainActivity.kt
+++ b/app/src/main/java/org/y20k/trackbook/MainActivity.kt
@@ -89,6 +89,7 @@ class MainActivity : AppCompatActivity() {
     }
 
 
+    /* Overrides onDestroy from AppCompatActivity */
     override fun onDestroy() {
         super.onDestroy()
         // unregister listener for changes in shared preferences
diff --git a/app/src/main/java/org/y20k/trackbook/MapFragment.kt b/app/src/main/java/org/y20k/trackbook/MapFragment.kt
index c15fa1e..bccb22a 100644
--- a/app/src/main/java/org/y20k/trackbook/MapFragment.kt
+++ b/app/src/main/java/org/y20k/trackbook/MapFragment.kt
@@ -60,6 +60,7 @@ class MapFragment : Fragment(), YesNoDialog.YesNoDialogListener {
     private lateinit var currentBestLocation: Location
     private lateinit var layout: MapFragmentLayoutHolder
     private lateinit var trackerService: TrackerService
+    private lateinit var sharedPreferenceChangeListener2:SharedPreferences.OnSharedPreferenceChangeListener
 
 
     /* Overrides onCreate from Fragment */
@@ -249,6 +250,21 @@ class MapFragment : Fragment(), YesNoDialog.YesNoDialogListener {
      */
 
 
+    private fun createSharedPreferenceChangeListener(): SharedPreferences.OnSharedPreferenceChangeListener {
+        return SharedPreferences.OnSharedPreferenceChangeListener { sharedPreferences, key ->
+            when (key) {
+                Keys.PREF_TRACKING_STATE -> {
+                    if (isAdded) {
+                        trackingState = PreferencesHelper.loadTrackingState(activity as Context)
+                        layout.updateRecordingButton(trackingState)
+                    }
+                }
+            }
+        }
+    }
+
+
+
     /*
      * Defines callbacks for service binding, passed to bindService()
      */
@@ -259,7 +275,8 @@ class MapFragment : Fragment(), YesNoDialog.YesNoDialogListener {
             trackerService = binder.service
             bound = true
             // register listener for changes in shared preferences
-            PreferenceManager.getDefaultSharedPreferences(activity as Context).registerOnSharedPreferenceChangeListener(sharedPreferenceChangeListener)
+            sharedPreferenceChangeListener2 = createSharedPreferenceChangeListener()
+            PreferenceManager.getDefaultSharedPreferences(activity as Context).registerOnSharedPreferenceChangeListener(sharedPreferenceChangeListener2)
             // start listening for location updates
             handler.removeCallbacks(periodicLocationRequestRunnable)
             handler.postDelayed(periodicLocationRequestRunnable, 0)
@@ -267,7 +284,7 @@ class MapFragment : Fragment(), YesNoDialog.YesNoDialogListener {
         override fun onServiceDisconnected(arg0: ComponentName) {
             bound = false
             // unregister listener for changes in shared preferences
-            PreferenceManager.getDefaultSharedPreferences(activity as Context).unregisterOnSharedPreferenceChangeListener(sharedPreferenceChangeListener)
+            PreferenceManager.getDefaultSharedPreferences(activity as Context).unregisterOnSharedPreferenceChangeListener(sharedPreferenceChangeListener2)
             // stop receiving location updates
             handler.removeCallbacks(periodicLocationRequestRunnable)
         }
diff --git a/app/src/main/java/org/y20k/trackbook/Trackbook.kt b/app/src/main/java/org/y20k/trackbook/Trackbook.kt
index 08dd3f3..cc9615d 100644
--- a/app/src/main/java/org/y20k/trackbook/Trackbook.kt
+++ b/app/src/main/java/org/y20k/trackbook/Trackbook.kt
@@ -38,7 +38,7 @@ class Trackbook: Application() {
     override fun onCreate() {
         super.onCreate()
         LogHelper.v(TAG, "Trackbook application started.")
-        // set Day / Night theme state
+        // set Dark / Light theme state
         AppThemeHelper.setTheme(PreferencesHelper.loadThemeSelection(this))
     }
 
diff --git a/app/src/main/java/org/y20k/trackbook/helpers/AppThemeHelper.kt b/app/src/main/java/org/y20k/trackbook/helpers/AppThemeHelper.kt
index 74a4787..9500951 100644
--- a/app/src/main/java/org/y20k/trackbook/helpers/AppThemeHelper.kt
+++ b/app/src/main/java/org/y20k/trackbook/helpers/AppThemeHelper.kt
@@ -1,7 +1,7 @@
 /*
  * AppThemeHelper.kt
  * Implements the AppThemeHelper object
- * A AppThemeHelper can set the differnt app themes: Light Mode, Dark Mode, Follow System
+ * A AppThemeHelper can set the different app themes: Light Mode, Dark Mode, Follow System
  *
  * This file is part of
  * TRACKBOOK - Movement Recorder for Android