Ab app
Limited to abs, but for what it is, the app is great. It offers three different length options with three different levels of intensity. The shortest and easiest is not too easy, so completing it will make you feel that you really did get a workout accomplished. As you progress and your strength and endurance increase, this app will allow you to grow your workout. And the longest workout is still only 10 minutes long, so you have no real excuse for not doing it.
Workout laggard about
7 Minute Ab Workout Daily Sit Up Exercise