TabDrawer from Winslow DiBona is an open source Swift based iOS component for creating tab bars with an added slide-out drawer for displaying more options in the user interface.
With TabDrawer options can be added to each tab bar selection that are shown when the user selects an option. This makes for a great way to make use of initial screen space.
This animation from the readme shows the concept in action:
You can find TabDrawer on Github here.
A nice custom tab bar component.