Android app restarts when opened by clicking app icon

Add this to your launcher activity:

if (!isTaskRoot()) {
    finish();
    return; 
}
super.onCreate(savedInstanceState);

I found it. I had set a flag android:launchMode="singleTask" in my activity flag. I deleted that code.

I also added onsaveInstance method to all the activities in my code and it's working now!

Thanks :)