[FitFu is now closed. Here's the original description. It was one of the first gamified fitness apps]
Track your motion
Using the accelerometer on your iPhone or iPod Touch, FitFu gives you feedback to help you keep going and reach your goals.
Celebrate progress with friends
Friends are the key to sticking to your goals, so we've made FitFu social; whether you want to cheer them on, thank them for help or just compare your progress.
Discover a new way to stay motivated
The more you and your friends are active, the higher your level and the higher your points. Unlock new content as you progress.
Stay active wherever, whenever
No more being tied to a games console or a gym, now you can stay active wherever you are - be that your bedroom, your office, a hotel room or in the cabin of your Mississippi boat.