Drupe - Next generation contact manager and dialer.
Simple Contacts - Contact lens prescriptions from home
FullContact Card Reader - Automagically scan biz cards into LinkedIn/Gmail contacts
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.
GNOME Contacts - All your contacts in one place
Truecaller - Find a person by a name or phone number worldwide for free using Truecaller.