So I want to buy all the episodes of The Walking Dead on my iPad. Problem is, I don't have wifi where I am right now. I probably won't for a few months. I see that I can download the app over iTunes and I'll be able to sync it to my iPad. What I do not know is, how can I purchase and download the episodes once I have the app on my wifi-less iPad? I don't see any options to do it on my iTunes.