You would exercise more if you were paid to, wouldn’t you? GymPact lets you put your money where you mouth is. Designed by two Harvard grads, the app rewards gym bunnies and penalizes couch potatoes. You commit to a quota of workouts – say, three a week, at least 30 minutes each – and choose a penalty (anywhere from 5 to 20 bucks) that you’re willing to incur every time you fall short of your goal. (The fee is charged to your credit card.) To rack up points, check in with the app every time you hit the gym. Or if you want to work up a sweat in the great outdoors, an integrated feature called Runkeeper tracks the miles and minutes that you spend jogging or riding a bike. (GPS keep you honest.) For every week you stay on track you receive roughly 75 cents (courtesy of fellow app users who chose Survivor over spin class.) Fitness has need been so rewarding.
To buy: Free, iTunes