I am just back to owning an iPhone after a few years of having an Android. I remember on iOS 5 or iOS 6 when I had an iPhone 5, there was a way to back up the signed cert that apple put on my exact device for that exact release of iOS, so that once you upgrade, and apple stops signing, you could still revert. I am on 10.1.1 now and thinking that when 10.2 comes final, I will prob go to that, *but* if there's that rare chance that later a jailbreak comes out for 10.1.1 but cant work in 10.2, I'd love to be able to simply go back to 10.1.1. Is this still possible what I describe above? How? Thanks.