Chord NOTE - Easily find the right chords to match a melody or musical phrase.
Captain Chords - Write chord progressions in your favorite DAW
Plugin Boutique - Inspirational MIDI effect that makes finding chords and progressions intuitive and fun
Odesi - ODESI is a music sketchpad that exports your projects to Audio and MIDI.
Chordjam - Creative music composition tool for desktop and iPad.
Cthulhu - VST MIDI-FX plugin for harmonic inspiration