I'm quite familiar with the music theory behind all of the scales, having played instruments for over 30 years, but I'm not finding the information display or interface to be very intuitive.
I also wasn't sure what effect some of the controls were having, but I think it might be because I am on my phone.
- the hover effect makes the lighter color buttons seem to disappear, especially once pressed
- I have no idea what the R button does or why
- pentatonic major is an uncommon scale and odd choice for default - pentatonic minor might be better, or just major
One thing I want to mention is that tool tips or other onscreen help would be useful.