Although the iOS 8 was a brilliant piece of work and came with its own advantages, there were a lot of aspects that needed improvement and attention from Apple.
The developers then came up with the iOS 8.1, soon after the original OS was released, but yet, all the bugs were not removed.
People’s expectations on the subject were left unfulfilled, leaving Apple with the task of righting all the wrongs.
Hence they came up with the iOS 8.1.1 to try and rectify the mistakes of the iOS 8.0.1.
Although a release date for iOS 8.1.1 has not been decided yet, we may be able to see the iOS8.1.1 beta version soon.
This is because the iOS 8.1 was a much bigger update and was in the beta phase a few weeks prior to being tested.
The iOS 8.1.1 is thus, expected to come in by the end of the month.
With any device supporting iOS 8, the iOS 8.1.1 would work well. The beta update is available for iPhones working on the iOS 8 as of now. So the devices that can work on the beta version are iPhone 6, iPhone 6 Plus, iPhone 5S, iPhone 5C and iPhone 4S.
Although a changelog for the iOS 8.1.1 is currently unavailable, it would definitely come with a lot bug fixes.
The iOS 8.1 would come with many improvements for the iPhone 4S and iPad 2 and it is expected that all problems would be resolved with no further issues.
However, all jailbreak fans must refrain from using iOS8.1.1 because the jailbreak from Pangu would not work if you install this update.
This is because this update cannot be rolled back and it seems to be a jailbreak free version, so once this update is made, there is no going back to iOS 8. So if you want to try the jailbreak, then stick to using the iOS8.
Source : http://www.therem.org/ios-8-1-1-top-ten-features-that-every-user-must-be-aware-of/1220163/