Troughton-Smith managed to hack the iOS simulator to enable the keyboard. It's activated by edge-swiping and features shortcuts for cut, copy, paste, and undo. Notably, the keyboard has been there since iOS 8 but never enabled by Apple.
Today's fun hack (been there since at least iOS 8); the iOS keyboard has an unused left/right one-handed mode. Activated by edge-swipe
Take a look at a few screenshots below.