Betting on people's gambling instincts, the
Gym Pact app is simple: Decide how many days this month you will go to the gym and ante up your money. Hit your goal and you hit the jackpot, raking in your own cash, in addition to that of less diligent gym goers.
If you miss your mark, the tables are turned and your cash gets redistributed. If better health doesn't compel you to exercise, then maybe losing some money will?
Free, available on iTunes