diff --git a/app/src/main/java/tonio/noa/TutorialScene3Activity.java b/app/src/main/java/tonio/noa/TutorialScene3Activity.java
index 4ac58c1..d660a18 100644
--- a/app/src/main/java/tonio/noa/TutorialScene3Activity.java
+++ b/app/src/main/java/tonio/noa/TutorialScene3Activity.java
@@ -16,6 +16,7 @@ import android.widget.ImageView;
 public class TutorialScene3Activity extends MyPlayActivity implements View.OnTouchListener, View.OnDragListener {
 
     private int win_counter = 0;
+    private boolean done = false;
 
     @Override
     protected void onCreate(Bundle savedInstanceState) {
@@ -85,7 +86,7 @@ public class TutorialScene3Activity extends MyPlayActivity implements View.OnTou
 
             // the drag and drop operation has concluded
             case DragEvent.ACTION_DRAG_ENDED:
-                if (win_counter == 3) bravoPage(v);
+                if (win_counter == 3 && !done){done=true; bravoPage(v);}
                 break;
 
             //drag shadow has been released,the drag point is within the bounding box of the View
diff --git a/app/src/main/java/tonio/noa/TutorialScene4Activity.java b/app/src/main/java/tonio/noa/TutorialScene4Activity.java
index 9a2efdc..a407ba5 100644
--- a/app/src/main/java/tonio/noa/TutorialScene4Activity.java
+++ b/app/src/main/java/tonio/noa/TutorialScene4Activity.java
@@ -15,6 +15,7 @@ import android.view.View;
 public class TutorialScene4Activity extends MyPlayActivity implements View.OnTouchListener, View.OnDragListener {
 
     private int win_counter = 0;
+    private boolean done = false;
 
     @Override
     protected void onCreate(Bundle savedInstanceState) {
@@ -100,7 +101,10 @@ public class TutorialScene4Activity extends MyPlayActivity implements View.OnTou
 
             // the drag and drop operation has concluded
             case DragEvent.ACTION_DRAG_ENDED:
-                if (win_counter == 12) bravoPage(v);
+                if (win_counter == 12 && !done) {
+                    done = true;
+                    bravoPage(v);
+                }
                 break;
 
             //drag shadow has been released,the drag point is within the bounding box of the View
diff --git a/app/src/main/java/tonio/noa/TutorialScene5Activity.java b/app/src/main/java/tonio/noa/TutorialScene5Activity.java
index bbe03d6..744cb71 100644
--- a/app/src/main/java/tonio/noa/TutorialScene5Activity.java
+++ b/app/src/main/java/tonio/noa/TutorialScene5Activity.java
@@ -12,6 +12,7 @@ import android.view.View;
 public class TutorialScene5Activity extends MyPlayActivity implements View.OnTouchListener {
 
     private int win_counter = 0;
+    private boolean done = false;
 
     @Override
     protected void onCreate(Bundle savedInstanceState) {
@@ -56,7 +57,8 @@ public class TutorialScene5Activity extends MyPlayActivity implements View.OnTou
             } else view.setBackgroundColor(0xff888888);
             return true;
         }
-        if (win_counter == 4) {
+        if (win_counter == 4 && !done) {
+            done = true;
             this.bravoPage(null);
             return true;
         } else
--
libgit2 0.21.2