Flexibits - Makers of Cardhop, Chatology, and Fantastical.
FullContact Card Reader - Automagically scan biz cards into LinkedIn/Gmail contacts
Apple Contacts App - Access and edit your contacts from personal, business, and other accounts with the Contacts app.
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.
Kin - Kin is money for the digital world. It is used to generate value through a shared, decentralized cryptocurrency in a digital ecosystem of apps and their users.
Nextcloud Contacts - The Nextcloud contacts app is a user interface for Nextcloud's CardDAV server.