Apple just stopped signing with iOS 9.0.2 code after iOS 9.1 was released last week, just to prohibit users from downgrading to the older operating system version. Yeah, in other words, you cannot downgrade to iOS 9.0.2 or older if you are not satisfied with iOS 9.1. So think twice if you want to upgrade to iOS 9.1.
But if you adhere to update your iDevice to iOS 9.1, you have to do a full-backup for your iPhone or iPad just in case of data loss, for with the backup, iFonebox can still help you to restore those lost data like photos, messages, notes and more from backup selectively.
Actually, it is not bad to update to iOS 9.1, at least, at present, not so many fatal bugs are found. Aside from stability improvements and fixes for bugs discovered in iOS 9.0.2, the latest iOS update released last week included a number of additional features. Owners of Apple's new iPhone 6s and 6s Plus, for example, receive a Live Photos enhancement that automatically senses when the handset is being raised or lowered to avoid recording unwanted movement. Also included is a list of more than 150 new emoji with support for Unicode 7.0 and 8.0 characters. By ceasing iOS 9.0.2 code signing, Apple is effectively blocking users from taking advantage of a recent Pangu jailbreak release. The exploit used by Pangu's installer was patched in iOS 9.2, according to AppleInsider.
