Hi @Allan B,
I've got your back on your query about the QuickBooks Online (QBO) mobile app.
You'll still have access to your QBO company via the mobile app. You only need to use the same credentials you use to log in to your browser.
Check out this article to see what features are available in the mobile app of QBO for supported devices: Compare mobile app features.
I'll be around in case you need further assistance. Drop me a comment below, and I'll get back to you.