Detecting Android Activity Launches

I have searched the stackoverflow for this question and found : Android, Detect when other apps are launched and Reliable way to detect application launch from home / desktop? , w

Solution 1:

Android default recent apps dialog implementation is best reference for you, look here..check reloadButtons()

finalActivityManageram= (ActivityManager)
                context.getSystemService(Context.ACTIVITY_SERVICE);
        final List<ActivityManager.RecentTaskInfo> recentTasks =
                am.getRecentTasks(MAX_RECENT_TASKS, ActivityManager.RECENT_IGNORE_UNAVAILABLE);

You can try in similar way..