Being able to add extra buttons is extremely useful for apps in which the user may be repeatedly entering words or odd symbols that can be difficult to enter using the normal iOS keyboard.
Previously I mentioned a nice open source for adding a row of single character keys above the keyboard with a look like native iOS keyboard keys called Quayboard.
Here’s a library that allows you to easily add letters and clickable words above the keyboard called ZRYWordPicker from Mariano Abdala.
The word menus created by ZRYWordPicker are scrollable so you can have a wide number of words.
Here are a couple of images from the readme showing ZRYWordPicker in action:
You can find ZRYWordPicker on Github here.
A nice component for extending the keyboard.