Electric chainsaw is a prank application with you feel as if you hold the real electric chainsaw in your hand.
Tap the screen to turn on the chainsaw, bring your phone close to anything with the device screen facing towards thing, when it is very close, you will notice that sound is changed as if chainsaw is cutting the thing. The logic behind this is that electric chainsaw application is using the proximity sensor. When something come close to this proximity sensor distance, chainsaw change the cutting sound.
Electric chainsaw is the best application to make joke and entertain your friends that will amaze to see that phone is given an illusion of real electric chainsaw.