Seven minutes doens't sound long until your thighs are on fire. I just downloaded and used the 7 app from Perigee. Here is the specs of this free app. The goal is to exercise 7 minutes for 7 months. As you do the workouts you unlock new workouts (or you can purchase them for $1.99). You exercise for 30 seconds and then rest for 10 seconds. The game part is you start off with three hearts. Every month you get 3 hearts. When you skip a workout, you lose a heart. If you miss three in a month, you're score goes back to zero. Here are some of the interesting information:  

7 Minute Workout “Seven” with High Intensity Interval Training Challenge - Perigee and their other app is Cycles - Period tracker with fertility calendar and reminders for both of you. - Perigee More stuff