Cardhop - The Mac contacts app you'll want to use.
ContactRescue - Magically get your address book up-to-date and accurate
Google Contacts - Google Contacts is Google's contact management tool that is available in its free email service Gmail, as a standalone service, and as a part of Google's business-oriented suite of web apps Google Apps.
Wall Of Me - Wall of me: all your favorite socials in a single place.
Contalist - The contact app for professionals and small businesses
Clearbit Connect - Clearbit Connect is a free extension that surfaces actionable information on the people who email you.