User-Agent Switcher is just great and exactly what I was looking for.
It does exactly what the name suggests, it also works on Firefox for Android and it is Free Software (GPLv3). Also, I appreciate the extensive description.

great add-ons

Best addon for mobile version. I use it for "Always desktop mode" option

Very good addon, works great most of the time. Do you think you could add more mobile options like Windows Phone or LineageOS?

Hi,love it however feature request for keyboard shortcut to change the string manually while still preserving random mode, sorry dont have a gitlab account

Firefox for Android does not have an option to always show PC version in the settings, but this add-on allows you to always show PC version, which is very useful for tablet.

really helps me with work

Works perfectly. I can access subscription based forums with this :D

Jaj cool

Please, add other browsers, yandex, opera ...etc.

in my case it doesn't help. on some particularly "especially smart" sites (in mobile versions of which, for example, the capabilities are limited), when choosing the user agent windows, it still says that I’m logging in from my phone.

Lo use para que el navegador de mi tableta muestre las páginas como un navegador de escritorio. Asi provecho mejor la pantalla, y tengo todas las funciones de escritorio

Causes a gigantic memory leak.

I never remembered downloading it I guess support did. It BLOCKED me from doing something(for me specifically it was the CloudFlare human verification). Only after troubleshooting FireFox and removing everything but it and adblock did I finally remove it and the problem was solved instantly. So if you are having problems with something and this is on the browser remove it and I believe unless it is an actual error it'll solve it for you.