While familit do have a browser / content manager add-in, this is a paid product (if you are looking for free family browser, check out tools4revit).  However, the family content itself at familit is free:
At the moment familit.com offers 18.000 free families in English, German and French language.


You don’t even need to register.  Just go to the following link and start downloading:
familit – Revit Family Library