Just add a sibling element with .nav-toggle and data-target to reduce one or more navs to a hamburger menu () on smaller screens.
Add .nav .sidebar to a block level element for a vertical navigation menu.
Add .popup for popup menus, rather than the default accordion style.
Add .popup.auto-accordian for popup menus on larger screens, which become accordion style on smaller screen.
Add .right to the <nav class="nav sidebar"> element for arrows on the left. In this demo, we use float:right to position the nav, but this is arbitary, as it is up to you to position the nav appropriately to your needs.
Add a button with .dropdown-toggle & add a sibling <ul> tree for dropdown support. It must be placed in a .horz-group or have position: relative; style set. Sorry, submenus not supported just yet.