The concept is simple, but it's surprisingly fun. Use the iPad 2's gyroscope to pull blocks from the Jenga tower and build it up. It's also got a fun Arcade mode that lets you compete for points. If you're looking to show off the iPad 2 to a group of your friends, Jenga HD is the game for it - it has a four-player pass-around mode that'll let your friends get their mitts on the iPad 2, but leave them wanting more as they pass it along.
Find Jenga HD here on the iTunes App Store.