Hey I thought with this app that you could play other ppl in the multiverse. How do I do that?
I don't think you can
You can't play people. You can play walls games. That's it. If you want examples of what wall games are, just go to the "wall games" section in the main menu and take a gander. It's not like cockatrice.
To actually play a game of MtG would be an infringement of copywrite laws. Cockatrice skates around it (but I'm personally still not convinced).
Wall games are the closest we have, it's like a faster "chess by mail" idea.