What Note Is This is a full version multimedia app designed by Ben Thornburg for iPhone users. The app is perfect for anyone who wants to learn how to read music or is studying an instrument. The app is highly recommended by several websites, including PadGadget.com and AppsForHomeschooling.com.

The app offers two learning modes: practice and quiz. In practice mode, users can flick through endless flashcards of notes, and the lights on the piano turn green when they press the correct key. In quiz mode, users can take 10-note quizzes with fast-paced auto-card-flicking action, and the lights turn red and green to show their accuracy.

The app also offers an adaptable learning environment, making it easy to focus on specific areas like bass clef. Users can turn off big letters on the keys or stick with the beginner mode if they're not ready for sharps and flats.

What Note Is This is suitable for all ages, and users can collect stickers for their accomplishments, such as identifying 10 notes in less than 20 seconds or identifying every sharp and flat during a quiz. The app is optimized for all devices, including the iPhone 5 display, and users can contact the developer with suggestions or questions through their website.