Use the following icons (in the header the top of the screen) while viewing your Gmail Inbox:
Accounts
and labels Tap to change to another account or label.
Compose Tap to begin a new Gmail message.
Search Tap to search within your Gmail messages.
Menu
options Tap to access Refresh, Label settings, Settings,
Send feedback, and Help.
You can also drag the screen downward to refresh and check for new email.