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.
Simple Contacts - Contact lens prescriptions from home
Open Contacts - Open Contacts is an advanced address book program for managing contact info of individuals and...
Nextcloud Contacts - The Nextcloud contacts app is a user interface for Nextcloud's CardDAV server.
FullContact Card Reader - Automagically scan biz cards into LinkedIn/Gmail contacts
Windows Contacts - Windows has many extraordinary organizers, and in the event that you include distributed storage, then you presumably have more.