Volume keys are not just for changing volume. It is also for locking apps now. Oops! application locker does not use any on screen password ie. pin based or a pattern based locking system. We use volume key pattern as the password. You can make any pattern using volume keys, like UP UP DOWN UP. - Oops Applock is Totally invisible. - Oops Applock ScreenLock is most safest screenlock. - Using Oops Applock ScreenLock nobody can unlock your phone. - Using Oops Applock ScreenLock nobody even notice phone is locked. - Oops Applock ScreenLock has different styles to choose. - Oops Applock is Most secure way to lock apps. - Nobody even notice your app is locked with Oops Applock. - Oops Applock is Simple. - Oops Applock is Fun to use. - Oops Applock can lock any applications. - You can set different background for lock screen on every locked App with Oops Applock. - Transparent and Black background makes as if your application is stuck. - Fool friends with custom backgrounds using Oops Applock. Tip- While choosing custom background, make sure it matches with your screen size to avoid clarity of the image.