Great App
Works great for me and so far is the best one I found in a way that u can customize your training, plus it has a big variety of exercises. I just miss a feature to create exercises and also combine them in drop sets and/or super series .. Despite that last comment is a great app. No bugs so far for me ( also with a 4 S).
GuiMedrado about
Fitness Trainer - Exercise & Workout Guide, v1.0.4