This app is easy to use and straight to the point. The ads do not pop up in the middle of your workout but right after you hit the "Save & Exit" button. It has a new challenge for you everyday with rest days in between. This helps you build the definition you are looking for from beginner to advanced. Once you finish 1 day you can skip along to the next day. I however am following the regimen and cant wait to see my results after the 1st 30 days! Great app!
Kayrwojcik about 30 Day - Squat Challenge, v4.7