Request Full Screen for Mobile/Desktop — Calva

A button appears on top right to request website to go full screen. Click it again to get out of full screen. Useful mostly for reading long web content like the news, books, emails, magazine articles, etc.

Currently only supported through Firefox Nightly. Follow the instructions below to allow Add-Ons to run on your mobile devices:
https://blog.mozilla.org/addons/2020/09/29/expanded-extension-support-in-firefox-for-android-nightly/

*** Since the full screen is requested on the current page, if page is reloaded or a link is clicked, it will exit full screen automatically and you would have to click the button again to enter full screen. Firefox blocks full screen requests without any prior user input.