I love how you can choose from a small variety of similar exercise for each 30 second interval before starting your workout. iOS also great that you can customize your workout based on the equipment you have on hand (or feel comfortable using). There are also helpful videos of each exercise that you can watch before starting but, even better, they play as you are working out so that you can check your form as you go. I only have one issue with the app. Every time I restart the app it shows Day 1. I have to scroll to the proper day. The history still shows all of my past workouts but I always start back at Day 1. This seems like an easy-to-fix glitch and I hope that happens in the next update.