Company The Royal Conservatory of Music created these great apps:
Smart Start, YouthBeat, RCM Music Theory Preparatory, RCM Music Theory Level 1–Lessons and Games, RCM Music Theory Level 2–Lessons and Games, RCM Music Theory Level 3–Lessons and Games, RCM Music Theory Level 4–Lessons and Games, RCM Music Theory–Intervals, RCM Music Theory–Notation, RCM Music Theory–Rhythm, RCM Music Theory–Scales, RCM Music Theory–Chords, RCM Music Theory–Melody, RCM Music Theory–History, RCM Music Theory–Terms, and others..