diff --git a/app/src/main/java/com/ericsson/uecontrol/gui/MainActivity.java b/app/src/main/java/com/ericsson/uecontrol/gui/MainActivity.java
index e4e4883..b02d615 100755
--- a/app/src/main/java/com/ericsson/uecontrol/gui/MainActivity.java
+++ b/app/src/main/java/com/ericsson/uecontrol/gui/MainActivity.java
@@ -5,8 +5,6 @@ import android.content.Context;
 import android.content.Intent;
 import android.content.SharedPreferences;
 import android.content.SharedPreferences.OnSharedPreferenceChangeListener;
-import android.content.pm.ApplicationInfo;
-import android.content.pm.PackageManager;
 import android.os.Bundle;
 import android.os.Handler;
 import android.preference.PreferenceManager;
@@ -21,7 +19,6 @@ import com.ericsson.uecontrol.core.UeControlExecutor;
 import com.ericsson.uecontrol.core.behaviour.UeBehaviourSleep;
 import com.ericsson.uecontrol.core.behaviour.UeBehaviourSurfing;
 import com.ericsson.uecontrol.gui.fragments.BehaviourListFragment;
-import com.ericsson.uecontrol.gui.fragments.NavigationDrawerFragment;
 import com.ericsson.uecontrol.gui.fragments.StatusFragment;
 import com.ericsson.uecontrol.gui.util.CSVWriter;
 
@@ -42,6 +39,7 @@ public class MainActivity extends FragmentActivity implements OnSharedPreference
     /** Fragments **/
     private StatusFragment statusFragment;
     private MenuItem action_execute;
+    private MenuItem action_mark;
     private boolean backButtonPressed = false;
 
     private static UeControlExecutor currentExecutor;
@@ -54,6 +52,7 @@ public class MainActivity extends FragmentActivity implements OnSharedPreference
     protected void onCreate(Bundle savedInstanceState) {
         super.onCreate(savedInstanceState);
         // Set static fields
+        PreferenceManager.setDefaultValues(this, R.xml.preferences, false);
         uid = getApplicationInfo().uid;
         context = this;
 
@@ -139,6 +138,7 @@ public class MainActivity extends FragmentActivity implements OnSharedPreference
         actionBar.setNavigationMode(ActionBar.NAVIGATION_MODE_STANDARD);
         actionBar.setDisplayShowTitleEnabled(true);
         action_execute = (MenuItem) menu.findItem(R.id.action_execute);
+        action_mark = (MenuItem) menu.findItem(R.id.action_mark);
         updateExecutionState();
 
         return true;
@@ -167,11 +167,18 @@ public class MainActivity extends FragmentActivity implements OnSharedPreference
             updateExecutionState();
             return true;
         }
+        else if (id == R.id.action_mark) {
+            if(csvLogger != null) {
+                csvLogger.addComment("--- Mark ---");
+                Toast.makeText(this, "Mark added to log", Toast.LENGTH_SHORT).show();
+            }
+        }
         else if (id == R.id.action_reset) {
             if(currentExecutor != null)
                 currentExecutor.reset();
             if(statusFragment != null)
                 statusFragment.reset();
+            csvLogger = null;
             updateExecutionState();
         }
         else if (id == R.id.action_edit) {
@@ -195,11 +202,14 @@ public class MainActivity extends FragmentActivity implements OnSharedPreference
         if(action_execute != null) {
             if (currentExecutor.isRunning()) {
                 action_execute.setTitle(R.string.action_stop);
+                if(action_mark != null && csvLogger != null)
+                    action_mark.setEnabled(true);
                 if(prefs.getBoolean("screen_on", false))
                     getWindow().addFlags(WindowManager.LayoutParams.FLAG_KEEP_SCREEN_ON);
             }
             else {
                 action_execute.setTitle(R.string.action_run);
+                action_mark.setEnabled(false);
                 getWindow().clearFlags(WindowManager.LayoutParams.FLAG_KEEP_SCREEN_ON);
             }
         }
diff --git a/app/src/main/java/com/ericsson/uecontrol/gui/util/CSVWriter.java b/app/src/main/java/com/ericsson/uecontrol/gui/util/CSVWriter.java
index 0638b73..ef5d1de 100755
--- a/app/src/main/java/com/ericsson/uecontrol/gui/util/CSVWriter.java
+++ b/app/src/main/java/com/ericsson/uecontrol/gui/util/CSVWriter.java
@@ -35,18 +35,20 @@ public class CSVWriter {
     private static final Logger log = Logger.getLogger(CSVWriter.class);
     public static final String[] HEADINGS = new String[]{
             "Timestamp", "Behaviour", "RX Throughput(b/s)", "TX Throughput(b/s)",
-            "RAT", "CellIds", "WIFI SSID", "WIFI RSSI"
+            "RAT", "CellIds", "WIFI SSID", "WIFI RSSI", "Comment"
     };
     public static final String DELIMITER = ";";
     protected static final SimpleDateFormat fileDateFormater = new SimpleDateFormat("yyyy-MM-dd_HH-mm-ss");
     protected static final SimpleDateFormat dateFormater = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss:SSS");
 
-
     private File file;
+    private String comment;
 
     public CSVWriter(){
         Context context = MainActivity.getContext();
         SharedPreferences prefs = PreferenceManager.getDefaultSharedPreferences(context);
+        comment = "";
+
         String path = prefs.getString("logging_path", "/sdcard/uecontrol/");
         if(!path.endsWith(File.separator)) path += File.separator;
         file = new File(
@@ -75,7 +77,10 @@ public class CSVWriter {
         line.append(getCellIds()).append(DELIMITER);
         line.append(getSSID()).append(DELIMITER);
         line.append(getRssi()).append(DELIMITER);
+        line.append(comment).append(DELIMITER);
         writeLine(line.toString());
+
+        comment = "";
     }
 
     protected void writeLine(String line){
@@ -88,6 +93,10 @@ public class CSVWriter {
         }
     }
 
+    public void addComment(String str){
+        comment = str;
+    }
+
     public static String getRat(){
         Context context = MainActivity.getContext();
         ConnectivityManager cm = (ConnectivityManager) context.getSystemService(Context.CONNECTIVITY_SERVICE);
diff --git a/app/src/main/res/menu/main.xml b/app/src/main/res/menu/main.xml
index a6ecb81..6d58d6b 100755
--- a/app/src/main/res/menu/main.xml
+++ b/app/src/main/res/menu/main.xml
@@ -6,6 +6,11 @@
         android:title="@string/action_run"
         android:showAsAction="withText|ifRoom" />
 
+    <item android:id="@+id/action_mark"
+        android:title="@string/action_mark"
+        android:orderInCategory="0"
+        android:showAsAction="never"
+        android:enabled="false" />
     <item android:id="@+id/action_reset"
         android:title="@string/action_reset"
         android:orderInCategory="50"
diff --git a/app/src/main/res/values/strings.xml b/app/src/main/res/values/strings.xml
index f4f6047..aa99ea5 100755
--- a/app/src/main/res/values/strings.xml
+++ b/app/src/main/res/values/strings.xml
@@ -31,5 +31,6 @@
     <string name="action_reset">Reset</string>
     <string name="pref_screen_on_summ">Keep screen on while execution</string>
     <string name="pref_screen_on">Keep Screen On</string>
+    <string name="action_mark">Add Mark</string>
 
 </resources>