About this app
Overview, features and application details
New music theory app (launched October 2025) built entirely on the guitar fretboard, with bite-size lessons, quizzes and a fretboard trainer.
Music Theory by Justin Guitar teaches theory entirely on the guitar fretboard. It's for players who've learned chords and songs but don't quite know why they work.
Lessons come in bite-size chunks with quizzes and a fretboard trainer that drills what you've learned. Everything ties back to the neck of your guitar, not abstract notation.
Launched in October 2025 and still growing, with about 16,000 installs so far. Made for guitar players who want theory that feels like it belongs on the fretboard.
