I installed a geoguess-server on my virtual server. On my Tablet I Installed this Geoguess-Instance as progressive Webapp via Firefox (like here). This is very nice! In this way, Geoguess is good playable with mobile Devices like Android Tablets.

Unfortunately I am not able to enter URLs via this progressive Web App, so joining a room, by enter the URL is not possible. There should be a third Button on the starting page, called "Join existing room". To implement progressive Web apps should be very easy then! :)