I wrote a few small Android apps using Kivy, and I ran into some problems with performance with scrolling lists of buttons. Doing it the most obvious, natural way led to obvious poor performance — a list of more than a dozen or so buttons simply could not be scrolled without accidentally clicking on one. There was a recommended workaround, which I found and used, and its performance was slightly less obviously bad — it showed up with dozens of bad reviews from users of slightly outdated devices. The last I looked, Kivy had not progressed on that issue. I didn't continue to use it, and don't know if it has other similar problems, but it was a discouraging experience for me.