Allows you to run up to 15 different cracked or leaked screens. Looks 100% real. People will have no idea it's just a prank app.
You can even keep using your phone with the crack active. Doesn't affect the phone's normal operation. Turn it off any time you want, or prank a friend by having it crack when they go to use your phone.
No real cracks take place. This app does no permanent changes to your device.