No specific info about version 4.0. Please visit the main page of ContactsSyncer on Mac Informer.
A better address book that makes contact management enjoyable for millions of people every day.
It exports contact data from the Apple’s Contacts app into various formats.
Import contact details from Excel or CSV documents.
Removes duplicated contacts in Address Book on Mac.
Apple Contacts SyncApps allows you to sync Constant Contact to Apple Mail.