From the Map screen, look for the History button at the top of the left row of buttons. It will bring up a menu of recently-accessed charts, so you can get back to the approach plate with only two button clicks (History>desired plate).
I also noticed when flying this weekend that from some screen(s), there was a "Plates" button, and when I pressed it it immediately took me back to the last approach plate I was viewing. I think I was either on a weather page or an Airport information page when I did that, but I remember being pleasantly surprised that the iFly seemed to read my mind!