BusyMac has released BusyContacts 1.0.3 with several helpful additions to the new contact manager app (see “BusyContacts Turbo Charges Mac Contact Management,” 17 March 2015). The update adds support for a tag extension that auto-fills the Attendee and Contact fields in BusyCal (requires the just-released BusyCal 2.6.6), adds a menu command for copying a contact’s
busycontacts:// URL, and adds envelope printing capabilities. BusyContacts 1.0.3 also improves the URL handler to support creation of new contacts, switches Facebook and LinkedIn syncing to
the AddressBook framework (due to the upcoming shutdown of the two social network APIs; see this BusyMac blog post for more details), improves background syncing and auto-linking, and displays a confirmation dialog when filtering by tag and deleting a contact. ($49.99 new from BusyMac or the Mac App Store (version 1.0.3 available soon), free update, 5.4 MB, release notes, 10.9+)
It is available in the Apple App Store now, and has been for a little while.
Apologies for not being complete. It's version 1.0.3 that will be available soon in the Mac App Store. I've amended the note to make it more explicit.