Marking the mobile browsers as "not supported" is somewhat accurate, as they aren't 1-to-1 with the desktop ones. To be technical, the Chrome iOS & Firefox iOS apps are closer to Safari in behavior, than other versions of Chrome/Firefox. This is due to Apple forcing all browsers on the app store to use the WebKit rendering engine & JavaScriptCore (the one Safari uses), instead of Blink/V8 & Gecko/SpiderMonkey , which Chrome & Firefox respectively uses everywhere else. The MacOS browsers doesn't suffer from the same limitation. Obviously updating the notification for mobile firefox/chrome to be more accurate & mention "table on tablet" would be better. TL;DR: All browsers on iOS are just Safari in a trench-coat. Roll20 doesn't support Safari.