The app is used for EAR and VOCAL exercises. It's a very professional music training app. You can do ear training and sight-singing practices. * The practices include pitch, interval, chord(includes inversions), scale, rhythm, melodic, etc. * The app record your practices, so you can know your scores anytime. * The app can remind you to do practices based on the learning schedule. * It's very easy to use for anyone. You can use it in anywhere and anytime.