I have an iPad 3 with unlimited ATT data plan. My wife has an iPad three with a 3gb ATT data plan. It turns out that most of my usage is on wifi (I checked my usage and consume less than 1gb/month of cellular data) and most usage for my wife is via cellular data (often exceeding 3gb/mo.) We would like to swap plans so that her iPad gets the unlimited data plan. We thought about swapping ipads, but we each use some different apps. If we need to exchange sims then won't we wind up with each others apps/accounts/itunes? How can we exchange data plans across these 2 iPads?