Cardhop - The Mac contacts app you'll want to use.
CiraSync - CiraSync is a program that syncs and shares office 365 GAL contacts and calendars to smartphones.
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.
Clariti.app - Clariti is a team communication app that uses Artificial Intelligence to combine emails, chats, documents, calendar events and feeds on the same topic, in rich context-based Conversations to ensure your communication stays focused & organized.
Keep In touch - Keep in touch with thousands of people
Socialsuite - Impact measurement with measured outcomes