You can't add another service as the app just shows the info for the Sim card you have in the phone.
This changed very recently. The Optus App can now show the same accounts that appear under a single MYACCOUNT login.
That said the billing system is still pretty fractured, so I can see my wife and my mobile accounts in the Optus App but I can't see our landline internet account (in MYACCOUNT I have to click on a button that leaves the new MYACCOUNT interface and goes back to the old one.)
@Margra, I believe the accounts have to be under the same billing address / account. You can transfer accounts under a single person if you want. Contact Optus LIVECHAT (probably in business hours) and see if they can get your MYACCOUNT online right first and the results should show up in the app.
I had seen this but didn't understand it was supposed to show all your services.
When I login it still only shows my phone, but not the other services I have in My Account - Home broadband and my wife's prepaid mobile.
All are under the same account no. so a little baffled. I wonder if you have to be on the new accounting system for it to work.