I play a lot of Guardian Cross on the iPad. It's a fun card game to pass the time with, so if you want to give it a try please feel free to use my invitation code below. The code will give you a free card, once you reach a certain level. I believe it's between level 5 to 10.

Guardian Cross IOS (ipad/iphone) invitation code: QX30139

When you start it up for the first time, make sure to enter the code, when it asks you for it, so you can get the free guardian.