ScreenTag - Digital business cards for professionals and teams
FullContact Card Reader - Automagically scan biz cards into LinkedIn/Gmail contacts
Haystack - Your new business card.
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.
Inigo - Digital business cards for individuals and businesses
Nextcloud Contacts - The Nextcloud contacts app is a user interface for Nextcloud's CardDAV server.