Linwood - https://github.com/LinwoodDev/Butterfly
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Saber notes is really good. It's more for notes, annotating PDFs and simple artwork than anything graphic design level though.
It's currently in early development and I don't know how well it works, but Xournal++ mobile is a thing. Its desktop app is really good, so I'd expect the mobile app to eventually get there aswell.
Edit: Whoops skipped the drawing part, Xournal++ is more for note-taking. Krita is a good choice for drawing.
Krita I don't draw so can't talk about the experience of using it
Krita doesn't have an Android app version though, does it?
Found this. I think it's pretty new.
https://play.google.com/store/apps/details?id=org.krita&hl=en_US&gl=US
Edit: the app link, not search results.
It's the full Kira desktop UI and app on Android. Digital pen drawing with pressure sensitivity works without further setup. The pen buttons don't seem to work natively. The version seems to be not the most recent Kira release (is the previous feature release instead).
I'll be using it. :)
Krita (Professionelles Malprogramm) https://f-droid.org/packages/org.krita/
I think they're looking for a new maintainer for the Android version, hopefully they'll find one but don't depend on it too much