Compatible with iOS 8 / 9 / 10
Do you feel the difficulty of typing on 5.5 inches devices with only one hand?
HandyKey, which resizes the iPhone keyboard, can make you type easier with one hand.
1) Swipe two fingers left or right to switch between different keyboard layout.
2) Use Activator. You can install Activator and set custom actions to switch between different layout.
Notice and Limitations:
1) Doesn't work with some apps which run with root permission (e.g.: iFile...)
2) Portrait keyboard layout only.
3) Doesn't work if the app doesn't have native resolution for 4.7 & 5.5 inches devices.
4) Doesn't work on any AppStore 3rd-party keyboards
5) Assistant keys wouldn't show on some keyboards (e.g.: Chinese Zhuyin & Emoji keyboard)