5 Apps That Will Pay You to Exercise More and Crush Your Weight-Loss Goals

Cost: Free

While the DietBet app is free, you'll have to place a bet to get money out of it (naturally). Once you've downloaded the app, you can either create a fitness challenge for yourself or join an existing one. If you meet your weight-loss goal in the allotted requirements, you can win back the money you put down, plus more.