Nice effort, a few tweaks needed
Add a “suggestions” feature where feature requests/changes can be suggested to you directly and not here in the review section.
Add a “How to use” section. I didn’t realise that I could scroll the keyboard left or right ( discovered by accident) to change the position of the first note on the screen, or play higher, lower notes. Add a settings section. Add Customise the colours of the keys in the scale away from the stock blue and green. (some people are colourblind, or would like the option ). Show suggested fingering ( complicated, I agree). Make the black keys to be played more obvious. They are so black that the addition of the blue (play this key) is not as obvious as it could be. Otherwise, it’s a great start, it just needs that 2.0 polishing.
A weird observation: when scrolling through the major scales, when it came back around to A, some of the notes were missing. Continuing to scroll, on some scales almost all of the notes were missing. What’s up with that?! I didn’t check other scales for this error as I’m not a paid software analyser.