I've used this for years. Easy to use, very nice. It is the only one I can find that would show all the cookies for the web page, and only those cookies. All others show the entire cookie database, unless you set filters, which are tricky and unreliable, and you cannot see all the host, domain, and subdomain cookies in one go as this add-in does, and most of them cannot filter by path like this one does.
But in my FF version 20 on Windows, it does not show any cookies at all, anymore. Did version 20 break it? I tried re-installing it but it's still broken.