I'm playing on an iPad using Safari. When I played against an opponent I could see their cards on their tavern mat and their cards in exile. My cards on tavern mat and in exile were invisible to me! (Also, thank you to whatever staff fixed the majority of the interface problems on iPad yesterday. It is much better and more playable now )
A tip I've heard is to disable the toolbar on mobile, such that the bottom area of the screen is visible from the game. This is where the windows for your "extra zones" reside.