hi , reported this the other day, and got below response yesterday about the bug (they also announced problem on Twitter):

"The reason that you are not able to log into your Odoo mobile app (showing a white screen) is because of a syntax-based bug that we are aware of.

This bug disrupts usage when accessing Odoo through Chrome mobile browser and the Android mobile app.

As a solution, for the time being, could I please ask you to access your Odoo mobile app using Firefox mobile browser?"

I've tried it, and it does work using Firefox browser on mobile device!