Clap! Whistle!
I got this because all the other Clap Camera apps sucked. I was surprised to see how well this one worked, and you can even whistle! Two feature requests here: 1) Please allow the timer (2s) to be configured to be longer. 2) Add a mic sensitivity option. You can make just about ANY noise and it will take a photo... so even clapping and whistling isnt necessary.
BobYourUncle about
CameraSharp - Anti Shake, Burst, Time Lapse, Self Timer Camera