You can see it work on Jumble.social. You just choose "login with bunker" and it displays a QR code. Open Amber up and scan the code with your phone camera. Done.
I'm constantly switching computers, but I always have the same phone.
Discussion
I tried this tonight. I did not think it worked because the QR stayed up, but after I x'd out if it it showed me logged in. Thanks. That is a really cool feature.