Lunar Racer from Noodle Cake is a very fun variation in the racing game genre. This app is designed for both the iPhone and iPad. It is currently free for download for a limited time. (normally $0.99).
You get to race your toy race in extraterrestrial race courses in a low G environment. The game uses a tilt and tap interface to control play. You have to navigate different hazards and pitfalls while picking up and using special tools along to way. There are 12 different race courses to explore and conquer.
Recommended for ages 7 and up. Younger children will be entertained by the app, but they will have difficulty mastering the multiple controls needed to play the game.