TL;DR -- Go to Hosted Demo
I wanted to learn AngularJS and Firebase. So I built this fairly simple Tic-Tac-Toe game to teach myself. I'm sure that the code related to both AngularJS and Firebase leaves much to be desired. Also, I didn't spend a lot of time styling things. Actually, once I got things mostly working, I pretty much abandoned development on the project altogether (after all, I only did it as a learning experience).
Still, perhaps you'll find it useful for your own purposes. If so, have at it!
For the code to work, you'll need my fork of angularFire, since (as of this writing) the upstream author hasn't yet merged my pull request.
Please submit a pull request!