Good Android Multiplayer Games?

I gave my old N7 to my gf when I bought the new one and now we're looking for fun multiplayer games to play. I'm talking about online multiplayer through Google Play, not handing one tablet back and forth. We found Hex, which was fun, but I was too good and now she won't play it any more : /

Anyway, I've looked all around and can't find any central location for finding multiplayer games. There is a "popular multiplayer" tab in the Google Play app, but it lists less than a dozen games.

Has anyone played good multiplayer games that they'd recommend?