On android, the former “Go free” app by AI Factory ltd, now simply called “Go”, lets you set up a game between two humans, using phone just like a portable go set.
Limitations are: no time control at all, limited number of moves on 19x19 (180 moves). No limits on 9x9 and 13x13.
It counts score at the end of the game and has a sort of score estimation always on in the top bar.
It can also display some sort of territorial influence during the game (it can be switched on and off at any time).
I found it very useful with beginners.
