Tenuto Music Theory
Rirpadev
Music Theory Companion
PG App Studio
MyMusicTheory - music theory
myrApps s.r.o.
音楽理論ヘルパー
johgru apps
音楽の理論
Kirill Sidorov
Music Pro
Sony Corporation
Thien Bui
触れる理論 (Touch Theory)
DarkChibiShadow
Math theory
Sangakoo
Fengshui Theory