To open an app, swipe up
on your favorites tray, then touch the app.
You don't need to close apps. Android manages the memory and battery that apps use, so you don't need to worry about leaving apps open.
To close one app, touch
to return to your home screen.
Touch
to see your recently used apps.
In your list of recent apps:
To search this help, touch
at the top of this page, and type keywords (like “add contact”).
If you don’t see what you’re looking for, check for app-specific help: