1st up is Chromatik, an app I just learned about that helps you transform the way you "practice, perform and learn music" A user has to setup an account at chromatik.com, which is entirely free. You can upload you sheet music share your music with your class or friends, Share practice recordings, and so much more. Seems like a great addition to any music class or musician. And the price is right!
Next, you may want to check out ProTuner (free at the moment I am writing this post). As far as I can tell all is said in the name. Tune your instrument using your preferred iDevice