From Roars Technologies:
Fatka is an application which is GAG of sound which can be used to play a gag with friends or colleagues.
You select a sound, set a timer and give iphone to your friend. As per the timer it will play funny sounds. Also you can select a sound and same can be done using Shake movement which will create sound on moment of iphone.
You can also take screenshot and select it from gallery so when viewing he will not get if its really a gag.