The service provides a list of the users followed by a Twitter user based on the number of tweets from that source marked as favorites. The preferred users are ranked in order by number of tweets favorited, giving a list in sequence by preference.
API methods support submission of a Twitter username with optional designation of desired output format. Methods return a listing of users preferred for that account. Default formatting in HTML shows each preferred username and account photo plus a count of tweets from that user marked as favorites by the username specified in the request. Various error messages are possible, depending on conditions of the requested username.