When iOS 8 was released, many users with older devices such as the iPhone 4S, iPad 2, iPad 3, and maybe some iPad 4 users found that the new software made their devices sluggish. Apple has been working hard at correcting this and has now released iOS 8.1.1.
I use an iPhone 4S from time to time, and I did notice how sluggish the device became when I downloaded iOS 8. When I learned that this new software was released, I quickly downloaded it and I can confirm that it has helped.
I haven’t had it installed long enough to know if all issues have been fixed, but it does definitely seem to be better now. If you have one of these older devices, try downloading iOS 8.1.1 and bring back some new life into your device.