Captain Chords - Write chord progressions in your favorite DAW
EarMaster - Professional software for ear training and practical music theory on Windows and Mac.
Odesi - ODESI is a music sketchpad that exports your projects to Audio and MIDI.
lightnote - An interactive site to learn the basics of music theory 🎶
Cthulhu - VST MIDI-FX plugin for harmonic inspiration
Touch Pianist - Play piano like a pro without playing piano.