Disable Preview of Pop-up Characters on IPhone Keyboard
Since its inception, iOS has always had small pop-ups for every key you press on your keyboard. If this feature has always bothered you for any reason, you’ll be glad to know that you can turn it off in iOS 9.
All you have to do is go to Settings> General> Keyboard and toggle the Character Preview toggle to Off. Now you won’t see these preview popups anymore.
How to Disable Preview of Pop-up Characters When Typing on the iPhone Keyboard | iDownloadBlog