R marks "relative" major/minor, for example: A minor pentatonic is relative to C major pentatonic (contains same notes/shapes, just root note is different). I can/could change defaults, but, all your presets should be saved between the sessions (your next visit). I am in the middle of making some interface changes, hopefully buttons will behave better after it. Thanks for feedback.

You're welcome, i may have some more feedback.

One thing I want to mention is that tool tips or other onscreen help would be useful.

I was thinking about tooltips but those are tricky to implement for mobile devices (although I haven't spend much time making it usable for small screens/devices)

True, i didn't notice the lack of hover tips until I used the desktop. But if it's oriented towards desktop, might as well put them in?