CircleBack - Contact sync application.
Windows Contacts - Windows has many extraordinary organizers, and in the event that you include distributed storage, then you presumably have more.
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.
BusyContacts - BusyContacts is a contact manager for macOS.
Apple Contacts App - Access and edit your contacts from personal, business, and other accounts with the Contacts app.
tinyblu - Never neglect your friends again. See how long it's been since you last hung out.