How is this for motivation: the DietBet app gives you the ability to win money by losing weight. Join a DietBet game, or start you own, and then each player places his or her bet (usually about a $25 entry fee) into the pot. Compete with others in your game to lose four percent of your body weight in four weeks. After the four weeks, winners split the pot evenly. The app allows you to track your progress throughout the game and see how you stack up against the competition.