I always thought that Men'sHealth had the best and, probably, one of the nearly most accurate taglines: "100% Useful". I receive their daily "Eat this, Not that" emails with awesome nutrition tips and in one of these emails I found a mini-ad for their iPhone App (Available at the iTunes Store for $1.99).
I used it for a workout today instead for my regular "muscle confusion" routine, and I can say that it's working awesomely. Plus, I think I needed a change in my workout routine... now I have many many many workout options to choose from. There's also the option of buying Expansion Packs if I ever get tired of these (many) workouts and exercises that come with the App.