Polymail - Native email app for email productivity.
RingCentral - RingCentral is the leading provider of cloud-based communications and collaboration solutions for small business and enterprise companies
Morning Mail - A new way to manage your mail. Tinder for email.
Dialpad - Switch is a cloud-based phone system built for Google Apps users.
Mailbird - Mailbird is the best email client for Windows 7, 8 and 10
Aircall - Aircall is a call center software of a new generation designed for fast growing companies. Setup instantly and integrates to your CRMs