Company Aktiv Systems created these great apps:
Music Theory Trainer, Absolute Pitch Trainer - perfect pitch exercises, Absolute Pitch Trainer - perfect pitch exercises, LOOKBOOK.official – создай свой имидж!, Absolute Pitch Trainer Phone Edition, Absolute Pitch Trainer for guitar, Note Trainer, Ear Trainer, Chord Trainer, Solfege Singing Trainer, Perfect Pitch Trainer, and others..
