While looking threw the manual again (and waiting on the new version :-) ) I thought about something that might be well worth thinking of for a version 2 maybe.
I realized that you had already "categorized" for yourself some styles in case of tempo. I wonder how much effort it would be to go further with this categorisation and add some typical style based scales/modes, chord progressions and other settings possible in the app already ?
And then offer a "simple" style selection as starting point. That would open the app up even for people who had nearly no music knowledge at all.
And as far as I know there are not many apps out there offering both ways: simply randomn and let yourself surprise what comes up (which is the center of the app now) AND to get started with a dedicated style in mind. It would even open up the app for some style based expansions later on.
Strangely that idea came to my mind while I was thinking about a little christmas song for my daughter as surprise (she is into christmas, I am the grinch :-) ) and then I woundered: what would be typical for a christmas song ? As my musical knowledge is very limited all that questions came to my mind: typical tempo, scale, progression, melody.....?