I don't know what to think as there is no icon available at all anywhere so I can't say it installed correctly. I bookmarked the options page so I could get to that but the hide icon is unchecked so it should be there I would think. If there is no icon is it not installed correctly?
Edit: I did find it in the dropdown menu where the three dots (...) are in the site address. If you right click on it you get the option to remove it form the address bar or manage it. If you remove it does it show up in the tool bar?

While I love this extension on Google Chrome, the icon for the Firefox extension seems to have disappeared. Resetting firefox doesn't seem to work, and as a result the extension can never do its job on Firefox.

This is one of the most comprehensive add-ons for geolocation out there. The various levels that it allows for configuration is unmatched.
However, it doesn't serve the purpose. For one, it says it allows you to configure per site but the icon that allows it is always disabled. It's not clickable no matter what option you choose. Moreover, albeit not much of an issue, it it embedded deep into page actions.
It also annoys me when it doesn't allow you to cache the location for infinite duration. I don't understand why deny the possibility if a user wants it.
Also, something that maynot be in it's purview is that a JS request as simple as one for system.time can help a website determine your geo-location.
Lastly, it doesn't work always. Websites such as iplocation.net can still determine your geo-location even when you have faked it using location guard.
I have used location guard in conjunction with and without other vpns but it has failed to do it's job consistently.
Don't get me wrong, faking geo location is a tough thing to do and this add-on does a job much better than any other, but it is still just not enough.

Most of the 1-star ratings are people who don't understand that this add-on doesn't affect IP-based locations.

This add-on works well and I definitely recommend the Fixed Location option for folks who need to tell nosy applications to look for the user someplace far way.

I do wish that the Fixed Location's Search capability would be implemented.

Works well on Firefox mobile Android

Well it works, but be nice to have the gps lat and log boxes to add the location there. Despite moving the location on the map it will put you somewhere else nearby, so takes some practice to get it right

Update
Well in firefox windows 10 im still getting asked to allow, even though its set to fixed, and its giving real location, this is on main pc, laptop is ok?

It works great. I've been using it for few years and love it.

It is not to hide or fake your IP location... it is for geolocation which is different. People gets confuse thinking that is going to mask their IP address location. For that you need a VPN or Proxy.

Really good product. For a bit I thought it was taken out from the Firefox Add-ons and I got scared looking for this again or an alternative, but couldn't find anything like this anywhere else.

Thanks for your work. It really works as you describe it. Love it