I have an S7 tablet. Yes, Krita works and I’ve been able to do some artwork with it.
A few things can be fiddly but all in all, it works fine.
(You can look at my posts from my profile to see what I’ve come across and a couple of paintings I’ve posted.)
I really like having Krita for Android though. Makes drawing more convenient.
I got an S6-Lite in December and use Krita on it regularly. I really like it because it’s so much more convenient than desktop. I’ve gone from using Krita every once in awhile to daily, when life allows. I waffled between a full tablet and a huion that can connect to whatever host (mobile, PC). I’m glad I chose a standalone tablet – it’s just one piece of gear to handle.
The screen real estate is cramped. It’s taking me a long time to figure out how to arrange the panels and tools to suit me. I’m probably only about half way to my local optimum, but even within these limits I’m sold.
There’s some things that are buggy and others that just aren’t possible (poster child: keyboard shortcuts). I can’t get the radial pop-up menu to work, but others report success. Fortunately folks are very helpful here in the forum, which has saved what’s left of my thinning hair from being pulled from it’s roots.
Save early and save often, be prepared to search and ask questions, be open to experiments and learning, and chances are you’ll have a great experience with Krita on Android. It’s only going to get better from here.