Prosopagnosia matches the names of the people tagged in Faces with the contact information found in Apple's Address Book, Microsoft Entourage, Google Mail or Mozilla Thunderbird. The program automatically transfers email and full name of the contacts back into Faces in order to complete the information required for a successful tagging of friends when uploading pictures to Facebook.
The user can choose to transfer information from more than one address book source. Prosopagnosia finds the best match and allows the user to ensure that the correct matches have been made through an easy to use Cover Flow interface. If the match found happens to be incorrect, the user can easily change to another contact suggested by Prosopagnosia.
Prosopagnosia also includes a backup feature, making sure that if something should go wrong during the transfer process, the user can always restore the Faces database to a previous working state.