Stark Gym Ball

Simple to use. Easy to adjust difficulty depending on each user's fitness level. Wish there was audio so I wouldn't have to keep straining to see the screen is my only critical feedback. Definitely worth using if you want to get a workout from your exercise ball and aren't sure where to start or have been using it for a while and want something to help with routine or adding new challenges.

If you are a no nonsense and get it done type of workout buddy this is a good app. I've got scoliosis and the exercises in here are core strengthening, balance training, and positive stretching to keep curvature of the spine in a strong posture working against gravity. Yay!

I enjoy the way you can set up your routines based on muscle groups. However it is sorely lacking in routines for lower legs, upper chest and upper back. Also, while doing the exercises it would nice to have either music in the background or coaching instructions on how to focus what muscle group, how place your feet, how to place your hands etc.