Drawer
The default navigation mode. There is a "hamburger" menu in the top right that opens up a drawer menu on the left hand side. From there you choose the view to navigate to.
Tabs
This is similar to the GMMP 2.x Holo theme's navigation mode. There is a navigation bar at the top with a bunch of tabs. The bar is scrollable left/right and all the options/settings are accessible from the 3 dot menu at the top right. Tab navigation has an optional search button available to toggle in the customize menu.