Do it's job

Very inconvenient way of importing the user agent in text form.

Hello! I decided to use your supplement. But the first thing I did not like was the lack of the ability to auto-update user agents. I thought I could solve this problem by manually adding agents through the site https://techblog.willshouse.com/2012/01/03/most-common-user-agents/ On this site there is a string display of agents for example:
"Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/60.0.3112.113 Safari/537.36
Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/61.0.3163.100 Safari/537.36"
But when I began to add them, they were wrong. It turned out that these lines should be edited and indicate which client is available in fact - dekstop or mobile ... It's not convenient! Is the add-on not able to determine whether the agent belongs to the OS on the line "... (Windows NT 10.0, Win64, x64) ..."?

Doesn't save the agents wich have been added by the user.

Wonderful extension ! Comprehension and Well-designed.

good, but lacks list with domains where disabled

Best user agent spoofer because it has random mode and you can add your custom entries (e.g. that are most popular to reduce fingerprinting).

Buen

с прокси не дружит. При включенном прокси и с вашей маскировкой проверяю на сайте http://ip.fri-gate.org/ru/ маскировка не работает данные пк видны FF58

把火狐伪装成 Chrome 手机版，终于能正常浏览百度文库、经验、贴吧等网站！

Using Firefox 52.5.0ESR and Java 8 Update 151 ... I can not get this web site to load the crossword puzzle.

https://www.seattletimes.com/games-nytimes-crossword/

It will work in Windows 10 using IE11 and was working just fine on Tuesday Nov 21, 2017
It has been reported to the site manager but they have not responded or corrected the issue.
I tried it using a few choices in User Agent Switcher, but it still did not load. Also, any chance to make
the UAS Button smaller ? ? ? It takes up a lot of room. Thanks

It also allows you to create custom UAs! (Not mentioned in doc but IMO important)

Very useful. Good to have. Only gripe is to add an option to change user agent every number of page changes. Like if that's set to 1, it will change the user agent every time a page is refreshed or a link is clicked. If set to 2, then after that happens twice user agent is switched. This, I think, would be a good addition to the random option.

nice agent switcher but it badly need a whitelist that set agent to default on selected website

This add-on changed my useragent but also broke other add-ons. External video player was one of them..it worked after I disabled UA switcher. Stable Firefox for Android..Note5.
Edit 1. Another add-on that seems to have abandoned stable Firefox on Android..I've noticed the trend. :-\ This works fine, so far, on Firefox beta. Please disregard one half of the 3★s I gave the add-on. It should be 2½★s since it only works on half of the Firefox browsers I use.

Won't work with Gmail, just because of that I give it 4 stars.

it works, but..
does not override appVersion, and platform + oscpu are parsed incorrectly for 64bit OS (they are displayed as 32 bit/x86/i686 instead of x86_64, etc..)