I have a GPD Pocket running Ubuntu 16.04 LTS with Unity and Firefox Quantum. The GPD pocket is a small netbook (7 inch display). For some sites I would therefore prefer seeing on this screen the mobile version of the website (mainly on my work's egroupware server).
How is this possible?
Bonus question (but neither necessary nor sufficient to get the accepted answer): How to do this on Google Chrome/chromium?
I do not care if this is a per website or a global setting as I use different firefox profiles for different things.