In ShiftNav (free), there will only be one option: Always visible. The submenu items will always be showing (you can choose to indent them in the menu settings).
ShiftNav Pro offers two additional types of submenus – accordion and shift submenus.
Setting the Submenu Type
You can set a global default submenu type, or a different submenu type for each menu item
Setting a global submenu type default
In the ShiftNav Control Panel, you can set a default Submenu Type. This submenu type will be used by any item in this ShiftNav instance that has its individual submenu type set to “Menu Default”. The individual item’s submenu type is set to Menu Default by default, so this will affect any menu items which have not had their Submenu Type Default set explicitly.
Setting a submenu type for an individual menu item
The submenu type can also be set on individual menu items in the menu item settings. The default is Menu Default, which will inherit the global setting from the Control Panel.
Remember, you set the settings for a submenu via the Submenu tab of the parent item Menu Item Settings
Accordion & Shift Submenu Types
Accordion submenus expand below the parent menu item, sliding down the contents below them. Accordion submenus are designated by a down-arrow. Here’s an example of an accordion submenu:
Accordion submenus are closed by touching the arrow to retract the submenu.
Shift Submenus shift a new panel over the top of the existing menu, so that only the parent menu item and its submenu become visible. Shift submenus are designated by a right-arrow.
In this example, ShiftNav Pro is a Shift submenu
Shift submenus are closed by touching the Back button in the menu.