I created this tool to learn fretboard notes as well as chord and scale shapes. I also wanted to improve my knowledge of music theory so I wrote all code related to theory from scratch instead of using libraries. While the latter is only beneficial for me, I hope that others find this tool useful for making music. I'd love to get your feedback.
One issue I'm aware of is that for non-diatonic scales (e.g. minor pentatonic) the shown triads are not correct. I just leave the triads for the last selected diatonic scale. What would you do? Hide them?