Gympact has an interesting spin on workout apps. It asks you make a commitment to get to the gym. You input how many days a week you want to exercise (minimum 1 day per week) and set the monetary stakes you’ll pay if you don’t go (minimum $5 per missed day). You receive money when you successfully complete a 30 minute workout. It’s not much, $0.30 to $0.50 per workout,...