"In honour of New Years Day, the ad free version of 'I'm Actin Here' is half price. The free version is also half price; half of zero, which is zero." - Wheezywaiter
The app is a mobile version of Charades that you can play with friends or connect with random players.
I haven't used it personally, but it looks like a neat concept.
Size: 31.6 MB
Compatibility: Requires iOS 4.3 or later. Compatible with iPhone, iPad, and iPod touch. This app is optimized for iPhone 5.
There is a brief explanation here:
http://www.youtube.com/watch?v=j80EEtZwER0
It has in-app purchases, but you most likely won't need them if you're any good at charades.