My toddler uses my old iPad 2 and it is running the original version it came with of ios. I want to download the Amazon video app, though it needs a newer version of ios. Not sure which one.... 1. Is there a way to upgrade the iOS one level from iOS 7 to 8 and not all the way to 10? 2. Will the thing become so slow as to become worthless if it gets upgraded to the latest version of iOS? Thanks.