Company LMuse Limited created these great apps:
Rhythm Cat Lite, Rhythm Cat Pro - Learn To Read Music, Rhythm Cat Lite HD, Treble Cat - Learn To Read Music, Treble Cat - Read Music, Bass Cat - Read Music, Bass Cat - Learn To Read Music, Rhythm Cat - Read Music, Treble Cat - Learn To Read Music, Bass Cat - Learn To Read Music, Treble Cat Lite, Rhythm Cat Pro, Rhythm Cat 2, Ear Cat - Music Ear Training, Ear Cat Lite - Ear Training, Bass Cat Lite - Read Music, and others..