I don't understand what this extension does.
After enabled it, shows that now i'm browsing from United States but my external IP was the
same as before i install/enable the extension.
So, what's the point of using it?
Also, because i clean the cookies, every time i click its button, it automatically opens its home
page for log in. This is very irritating. It should have an internal functionality for log in which
also should be compatible with Saved Logins manager of Firefox.
In private browsing mode also, it does not work at all. Even after logged in in its home page,
it remains disabled, opening again and again its home page every time i click the button..

[Updated]
This time i test it in clean profiles of firefox 55.0.3 and 62.0, both 64-bit and default settings.
The first time i click the button after installation, it opens its home page in a new tab (expected).
In here, i create a new account, verify the email address and log in. After that, when i click the
button, its pop-up remains open and i can enable it (the button becomes bright) and if i want, i
can also select a country (expected).
However, my external ip remains the same, as before installation/activation of the extension.
I check it by going here: https://bearsmyip.com/ and here: https://iplookup.flagfox.net/.
I tried to change several times the country, disable/reanable the extension but nothing was
changed.
Now, as of private windows, i can confirm again that it does not work at all. The first time i click
the button it opens its home page in a new tab where i log in. After that, every time i click the
button it does the same thing, bringing me again in its home page, where i am already logged in.