Missing the "append" mode and a confirmation check when you delete a existing user-agent string.
Apart from that, its fine and simple.

SEHR zufrieden, klappt so, wie ich will.
Manchmal allerdings settings völlig schwarz.

感覺有點耗資源 不過youtube上使用還是可以的

Работает. Но если в настройках видно Linux Firefox десктоп то определяться может как Apple Safari т.е. неправильно. Хотя реально Андроид Firefox. Меняет, но не точно.

good, but lacks list with domains where disabled

Buen

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

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..)

ok

当指定一个网站的ua后。当访问这个网站时候自动切换到设定的ua，而不是去手动修改。谢谢

Best one I've used so far, but the interface becomes messy if I want to add a lot. Please, dev, find a way to add the entries I want, and to check the box if I want them to show, and when I want to. And a way to add easily common new user agent without searching for hours on the internet, and fix the icon, I don't know if it's possible to make it multi-process.

I've used it with the entries found on: www.techblog.willshouse.com/2012/01/03/most-common-user-agents and tested here: www.whatismybrowser.com and here: www.whoishostingthis.com/tools/user-agent