Not sure if this is a bug, work in progress or intentional...
When I log in on another device (I have a phone and tablet, the phone is often used to messaging even with the tablet close at hand) I am logged out of the other device.
I assume that's some kind of security around purchase protection etc, but neither one saves my login info so I have to reenter it entirely.
It may also be nice to have the logout message explain why I am being logged out. I swear it happened once when I logged on to the forums but I haven't seen that duplicated.