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.

E-Z Contact Book - E-Z Contact Book is an easy to use yet powerful Windows application for managing contact information. You can use it as a personal contact address/phone book, business directory, or a customer database, or a reminder of birthdays and other events

Apple Contacts App - Access and edit your contacts from personal, business, and other accounts with the Contacts app.

Cardbox - Contacts reimagined as a social network ✨

Windows Contacts - Windows has many extraordinary organizers, and in the event that you include distributed storage, then you presumably have more.

Cat Facts - Get random cat facts in your Slack every so often 😸