Make them think they've broken your phone with Cracked Phone Screen! Or just show them a cracked screen you broke.
Once app is started you will find a broken glass image on top of your screen. Yes, it's just a joke, but it's a very good one if you borrowed phone of your friend and now ready to hand it back. Do you wanna see his/her scary face?
Again, Cracked Screen is a silly joke app which simulates a broken mobile phone screen. Make a fun out of each of your friends.
How to use:
Start "Cracked Screen" and once you see the cracked image, just hand your phone to one of your friends. That's when they'll notice the "broken screen" on your phone. You can even blame them for breaking your phone, maybe they'll buy you a new one ;)