I use “Sente - Online Go” and really like it. It shows as early access but I haven’t found any issues with it. It connects to the OGS server so you can play against bots of varying difficulty or normal online matches.

I used to use KGS, but that was mostly on the computer, though I know they also have an Android app. That was several years ago, though. My friend who still plays does so mostly on Pandanet via Android.

Those are both for multiplayer, of course. For single player, a while back I used Gridmaster along with a build of LeelaZero, and there are various apps that offer Go problems, including one my friend likes, but I have forgotten what he told me it was. I think it might be Tsumego Pro, but I’ll have to ask him again next time we talk.

Edit: Dragon Go Server probably deserves a mention as well. That’s a site for, basically, postal games via email, and can be accessed entirely via a web interface. It’s not as popular as the sites with faster time controls, but it’s kinda nice for playing a leisurely game with a busy friend.

I used to use gobandroid off f-droid, but these days I use crazystone: I like its ai for casual play (and I usually only play casual!). It does seem to have a deep love for talking home with no explanation when it starts up though, so on Lineage I just disable its internet permission.

Online-go is good but I haven’t really gotten into playing against strangers on the internet: I feel I should take it more seriously when I’m against a real person!

Wish I had people offline to play with sometimes though.

I was hoping someone would comment on this actually. Every android app I’ve tried has been riddled with ads to the point of being impossible to play.

If someone has a good one PLEASE let us both know!