Sidekick by Hubspot - Customer insight integrated with your email tools.
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.
HiHello - Exchange contacts, seamlessly.
FullContact Card Reader - Automagically scan biz cards into LinkedIn/Gmail contacts
Sansan - Sansan provides a internal contact sharing service for companies.
Nextcloud Contacts - The Nextcloud contacts app is a user interface for Nextcloud's CardDAV server.