I think you have to have one in order to get the credentials setup for an iOS app, I know that Android is free. Bad thing, I don't have an Android phone, I have a iPhone6 which I don't care for actually. It's too damned big for me. I like the size of the 5 much better. But I digress. Someone will have to see about getting one before push notifications can be set up for iOS devices because of the needed credentials. At least that's what it seems like to me from what I was reading.