View Mode

File Manager has two view modes: list view and grid view.

Grid view only shows file name and icon but can display more entries in one screen.

List view shows more file information, including folder children size, file length, last modified time and permission. Sometimes(especially in network environment) list view is a bit slower than grid view since it retrieves more file information which consume more time.

Use view mode button in toolbar to switch between list view and grid view.

Navigation

File Manager tracks your browse history. You can leverage following navigation buttons from toolbar to easily access files:

Goto home directory. The path to home directory can be customized in preferences page. Default home path is android external storage.
Goto parent folder of current folder. If there is no parent folder available, this button will be disabled.
Goto previous folder in navigation history.
Goto next folder in navigation history.
Goto external SD card. This icon will appear if your device uses a partition of the internal storage for the external storage and also offers an SD card slot, such as Galaxy S3. This icon is only available on android version 3.2 and above.

Multiple Tabs

File Manager support multiple tabs, different tabs can show different folder information independently. Each tab has its own navigation history. This is extremely useful when copy/paste files between different source and target folders.

Use tab icon in right-top corner of title bar to launch tab dialog.

Following is the tabs dialog:

Each tab contains its icon and path. Current tab is the highlighted one. You can single click on desired tab to switch file manager to that folder.

Create: Click create button to new a tab. The default path to new tab is android external storage.

Delete: Check checkbox after each tab, and click delete button to close them. You should at least keep one tab remaining.