This is an awesome app/game that tests how well you can hear the difference between two pitches. As a musician and singer it is very important to have good intonation. The foundation for good intonation is developing an ear that can recognize when a pitch is sharp, flat, or in tune. Play every day and improve your score and ear for intonation! The lower your percentage, the better your score! This app is free for a very limited time – download and check it out!