Provides basic functionality for free, but requires a $10/mo subscription for business contacts and stats displays. However, you can turn to the open source FOCA software to do a better job.

It works, but costs me ~100MB memory at start and eventually ~800MB and I found this after using it for more than 2 years.

It's amazing.

Great and really useful extension, but it really slows down the loading times of pages (have had this for quite some time now, and I have reported it before if I recall correctly), and thus I sadly cannot leave it enabled.

Руссофобские персонажи, блокируют с русских ip контент.

Glad to see this has made it over to FF.