Aural sense is the basic capability for music training. However, many music students usually ignore its importance. It's also very difficult for music teachers to cover all aspects in classroom. In order to solve this problem, the Ear Training Grade series provides a very good studying platform. The design of app focuses on interactivity and allows students to practice repeatedly whenever they want. The grade is ranked according to most major music exams in the world. It provides very useful supplementation materials and helps music learners to develop their musical ability.