So I found a way to install the mobile app, and I have a request - please allow us to save our login details, and make it easy to switch between multiple worlds !
Current situation on computer: I open my browser. It has tabs open to the EN, US and ZZ home pages, and I'm automatically logged in to each. I can open my various cities (EN1, EN2, US1, ZZ1) without having to enter any usernames/passwords.
(The only restriction is that I can't have EN1 and EN2 open at the same time, but even when I log out from one, I can go straight in to the other without entering details)
Current situation on mobile: I open the app. Select US server. Enter username. Enter password. (both of these on a fiddly mobile keyboard). Log in to US1. (do stuff). Log out. Select ZZ server. Enter username. Enter password. Log in to ZZ1. (do stuff). Log out. Select EN server. Enter username. Enter password. Log in to EN1. (do stuff). Log out. Enter username for EN again. Enter password for EN again. Log in to EN2. (do stuff). Log out.
Please make it easier to manage this ! I trust my phone and my app, let it remember my credentials after I've entered them once !