After a severe concussion left her suicidal and bedridden Jane McGonigal invented SuperBetter, a series of daily challenges that improve your physical, emotional, mental and social strength. Some challenges are as simple as drinking a glass of water or taking a walk around the block, others are more complex.
The iPhone app for this game is fun and easy to use although I do find the sound effects a little irritating. You can also play the game on the Super Better website itself.