Students in my school are not allowed to have iPods in school either, but I allow them to bring them to class for the days we are in our fitness room. There are a few apps I use to help out with making up workouts for PE classes or with my wrestling team: Crossfit Daily, Fitness Free, and Gorilla Lite. There is a good app to help kids with identifying muscles as well - 3D Musculoskeletal Quiz, and Fitness Muscle Mobile has great tips and video tutorials that show how to properly perform different weight training exercises.