If you want to take a quick break from work and have some online fun I cannot recommend @cardgames_io enough.
As you can infer from the name it gives you the possibility to play many classic card and board games against computer controller bots or other players.
I love how well it performs, the minimal ads it features, the total absence of mandatory accounts and IAP and the cute avatars and explanation videos from the games.
At the moment I'm playing Gin Rummy, easy to play but hard to master, as I like games to be.