Truecaller - Find a person by a name or phone number worldwide for free using Truecaller.
RingCentral - RingCentral is the leading provider of cloud-based communications and collaboration solutions for small business and enterprise companies
FullContact Card Reader - Automagically scan biz cards into LinkedIn/Gmail contacts
Dialpad - Switch is a cloud-based phone system built for Google Apps users.
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.
Aircall - Aircall is a call center software of a new generation designed for fast growing companies. Setup instantly and integrates to your CRMs