looks pretty good Rated 4 out of 5 stars

A flag will be shown discreetly in the address bar.
One click and showing the location of the server and the owner of a domain. Now installed. Works fine for me.

@Questy:
The AddOn "Status-4-Evar" brings back your statusbar.
https://addons.mozilla.org/de/firefox/addon/status-4-evar/

This review is for a previous version of the add-on (5.1.9). 

good good Rated 5 out of 5 stars

번역짱

This review is for a previous version of the add-on (5.1.9). 

Looks great but i have request Rated 4 out of 5 stars

Please return back possibility to move addon's icon from address bar to status bar (many people still use statusbar with addons)!!

This review is for a previous version of the add-on (5.1.8). 

It's pretty cute. Rated 5 out of 5 stars

Installed it right now.

This review is for a previous version of the add-on (5.1.8). 

+ Rated 5 out of 5 stars

Крайне полезное расширение! Благодарю!

Одно "но", при использовании TOR, как прокси по умолчанию для всего трафика - не отображается флаг(иногда и информация) сервера сайта...и даже не знаю как починить(что добавить в исключения..или еще каким-другим способом)...пишет - "Нет доступа к DNS"
В остальном - все в порядке!

This review is for a previous version of the add-on (5.1.8).  This user has a previous review of this add-on.

Works great! Rated 5 out of 5 stars

Works well, no complaints

This review is for a previous version of the add-on (5.1.7). 

Really Useful Rated 5 out of 5 stars

I love that I'm able to see what country a site is from and it's ip!

This review is for a previous version of the add-on (5.1.7). 

Works 100%, consistently updated for years Rated 5 out of 5 stars

Recommended

This review is for a previous version of the add-on (5.1.5.1-let-fixed). 

awesome addon Rated 5 out of 5 stars

most useful addon for checking ips.
even has icon for local ips

This review is for a previous version of the add-on (5.1.5.1-let-fixed). 

Salut Rated 5 out of 5 stars

ok

This review is for a previous version of the add-on (5.1.5.1-let-fixed). 

Rated 5 out of 5 stars

Достаточно информативное и удобное приложение

This review is for a previous version of the add-on (5.1.3). 

Rated 5 out of 5 stars

Handy functionality to have around.

This review is for a previous version of the add-on (5.1.3). 

Excellent, very useful Rated 5 out of 5 stars

Didn't know I needed it till I tried it! Very useful.

Right-click on the flag to get more options. Can also add your own. I added one for getting a site's Compete.com stats:

https://siteanalytics.compete.com/{baseDomainName}

This review is for a previous version of the add-on (5.1.2). 

Rated 5 out of 5 stars

Nifty little plugin, says Mr. Sakhai because it reveals hidden metadata, and all the general information that you might want to be informed about.

This review is for a previous version of the add-on (5.1.2). 

Excellent must-have Add-On Rated 3 out of 5 stars

But minus 2-stars, because I miss seeing more information when I hover mouse over the flag and I need to go to a 2nd website, before I can see any further information like SEO on the website.

I hope this will be added as an option in the future, that would show more instant information on the visited site other than it's server origin.

This review is for a previous version of the add-on (5.1.0).  This user has a previous review of this add-on.

Rated 5 out of 5 stars

Excellent and does the job. Thanks.

This review is for a previous version of the add-on (5.1.0). 

Rated 5 out of 5 stars

КЛАССНАЯ ВЕЩЬ !!СТАВЬТЕ НЕ ЗАДУМЫВАЯСЬ !!!

This review is for a previous version of the add-on (5.1.0). 

Rated 4 out of 5 stars

Good addon but i wish i could put it in the side menu along with other addons. I like my URL bar to be clean.

This review is for a previous version of the add-on (5.1.0). 

Rated 5 out of 5 stars

Very good addon! For now works perfect but i`m using it for about a day. Thanks we need good addons for best Browser!! :)

This review is for a previous version of the add-on (5.1.0). 

Signed or not Signed? Rated 5 out of 5 stars

Love this neat little extension.

I read somewhere that starting with FF 40 only signed extensions are allowed. Apparently FlagFox is still unsigned. Meaning that starting from FF 41 we cannot use it anymore. Is that true?

Thanks

This review is for a previous version of the add-on (5.1.0). 

Flagfox is signed, just like all addons on here

Flagfox is of course code signed by Mozilla now, just like every other public addon on this site.

My guess is that the reason you think this might've not been the case is the fact that the old addon files that were converted to signed when Mozilla switched over to this new policy all were given new version numbers with the addition of ".1-signed". This was annoying, but it's what they did to everything. New addon files which are uploaded to this site and approved by Mozilla do not have their version number tampered with. Mozilla only changed the old version numbers to force a massive wave of addon updates. New versions are already new and will be updated normally.

EVERY addon on this site which is approved by Mozilla is signed, now.

You can download any addon XPI from here, open it up (it's a glorified ZIP), and see that it has a META-INF folder with a signature in it.