Why you want it: If the fact that you’re wasting money on a gym membership that doesn’t get used isn’t enough motivation to get your butt into some spandex, then download GymPact -- it will actually give you money if you do workout. It works like this: each week you make a commitment to show up at your designated gym for a certain number of days. Then you set your stakes. For every day you fall short of your goal that week, you will be charged your wager (most people start with $10, but you can charge yourself up to $50 per missed workout). All the money you are charged goes into a pool of money funded by people (like you) who have let life (read: Happy Hour) derail their quest for rock-hard abs. When you show up at the gym, you check in via your phone (a la Foursquare) and you get paid out from that pool -- every time! Now that’s incentive.