The first time you run Phone Usage, it gives you some extra tips to make adding an account easy, and if you're using Phone Usage, tells you how to add more accounts.
This video shows how to add an additional account. In this example, an Optus mobile prepaid account.
This video shows adding an Optus broadband account, and the available settings.
The Favourite Account setting lets you choose an account that’s opened automatically when you start the app.
The Bar Display Mode setting changes the way usage bars look.