Mandalas draws chords in radial rings: a branch of chords repeats, transposed, around the circle until it forms the mandala, with colors by chord type and connection lines between them. It's free and opens without an account.
You type the chords of one branch, one ring per line, and choose how many semitones apart it repeats and how many branches there are in total. Then you adjust colors and connections, and export to PNG, SVG, or After Effects.