Now UI Kit - A beautiful Bootstrap 4 UI kit. Yours free.
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.
Bots UI Kit - Fully customizable Sketch UI Kit for Messenger Platform
FullContact Card Reader - Automagically scan biz cards into LinkedIn/Gmail contacts
Landing UI Kit - Handcrafted UI components for landing pages
Nextcloud Contacts - The Nextcloud contacts app is a user interface for Nextcloud's CardDAV server.