iKeywi is a tweak which can let you customize the keyboard on your iPhone.
> Adds an extra row to your keyboard
> Supports all languages (*)(**)(***)
> Supports both portrait and landscape mode
> Set keys as cursor mover and undo/redo function
> Compatible with iPhone 4/4s/5/5s/5c/6/6S/7/8 and X
> ...and more!