Here’s the link: https://play.google.com/apps/testing/io.zenandroid.onlinego
It’s a very early alpha, so many things won’t work (most notably issuing and accepting challenges). Also, the notification keeps coming back in a few hours even if you dismiss it (which is not intended) but all in all you should be able to use it to play correspondance games. Braver souls should be able to play live games too, just don’t abuse the last second too much
Any feedback is welcome, but due to some personal problems I might not be able to work on this very much in the next period.