What games on the app store let you play against friends
Dgunners ZZ just came out and has a PVP mode. I'm not sure if they've made it to where you can choose who you play against yet but it is really fun. Battle Bears and Battle Monkeys are also some player vs. player games.
Wheel of fortune
Dice with friends, words with friends, scramble, ruzzle
Words with friends and draw something
U should get Metalstorm:wingman it is awesome and u can play against friends it's a warplane simulating game takes up a ton of storage space though. and it's free :)