Hello everyone, I just got my very first tablet, a Nook HD. While I'm a long-time PC gamer with a nice desktop gaming system, I have absolutely no experience with any sort of tablets or smart phones or anything else of that sort. So without having to research everything from square one, I'm hoping some of you with far more experience with this sort of gaming can offer me some suggestions. I think the Nook HD uses an Android-based OS, but I'm not 100% sure. Also don't know any of the other specs except that I have the 16GB model.

So, without further ado, any game recommendations for a Nook HD? I love turn-based strategy games and MMO's in particular, but I'm open to almost any genre with two requirements:

1) I want to be able to play with or against other people. It can also have single player, but I want at least some real multiplayer content.
2) No micro-transactions. I want to pay X amount of dollars to purchase an entire game, and not need to wonder every time I play if I should spend more money to get more features or bonuses or whatever. I don't mind if the game has like, an expansion pack or something, but I want to be able to know an exact dollar amount the entire game, with no strings attached, costs in advance.

Another related question: where should I be buying/browsing for games from? Google Play store? Is there a better option?

Thanks in advance for the help!