Important Note (v0.1.8): in order to get the Flag and location of the website's server, this addon uses only a local database which is stored in the addon's package. Once you open the popup, it will show you more details about the current flag, plus, an static image showing the flag's country which is generated with Google Maps API. Moreover, there is a button in popup UI (bottom left corner) which opens the current domain in Alexa website. Alexa will show you more info about the current domain and its global ranking.
Some features of this addon:
1. Gives you the GEO info of the visited website's server (active Tab URL).
2. Supports more than 240 countries.
3. Has 3 different flag sizes (see Options page for more details).
4. Popup UI shows server's Geo country and location in a small map (derived from Google maps API).
5. The flag icon's tooltip text shows a brief info about the server's Geo location.
Note: in order to submit Bugs, please visit addon's homepage (http://mybrowseraddon.com/flag-plus.html) and fill the Bug report form.