> - Non-native widgets, Kivy draws its own widgets using OpenGL. They're quite customisable, but of course you never get behaviour quite like the native ones.
And this can make the application entirely unusable for some users. I'm thinking in particular about accessibility for blind users, who need to use a screen reader, though other disabilities are also impacted. Basically, to be accessible, an application's UI components need to implement the platforms' accessibility APIs. Most non-native widgets don't do this, because it's a lot of work that most developers just don't even think about. As far as I can tell from a quick scan of the source, that currently includes Kivy. So beware that if you use Kivy and its non-native widgets, you'll be locking some users, admittedly a small minority, out of your app. Probably OK for a game; not so much for an application that's going to be used in a job or education.
As a Kivy dev, I've thought about it before on the desktop (it's come up before and a gsoc student did some preliminary investigation for the best way to do it), but I'll admit I didn't realise the implications on Android where actually this support might be harder due to the mismatch with the normal java widget mechanisms. I do think it's important and will try to take a look at it, but it's certainly true for now that Kivy does not have much support for standard accessibility tools, probably particularly on android and ios.
And this can make the application entirely unusable for some users. I'm thinking in particular about accessibility for blind users, who need to use a screen reader, though other disabilities are also impacted. Basically, to be accessible, an application's UI components need to implement the platforms' accessibility APIs. Most non-native widgets don't do this, because it's a lot of work that most developers just don't even think about. As far as I can tell from a quick scan of the source, that currently includes Kivy. So beware that if you use Kivy and its non-native widgets, you'll be locking some users, admittedly a small minority, out of your app. Probably OK for a game; not so much for an application that's going to be used in a job or education.