FullContact Card Reader - Automagically scan biz cards into LinkedIn/Gmail contacts
Truecaller - Find a person by a name or phone number worldwide for free using Truecaller.
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.
Bluff My Call - Bluff My Call app provides features to allow users to make prank calls to their friends and family members by changing their voice and caller ID in a few simple steps.
Nextcloud Contacts - The Nextcloud contacts app is a user interface for Nextcloud's CardDAV server.
True Contact - True Contact is a special caller ID revealing app for those smartphone users who want to resolve their issue of unknown and unwanted calls.