RingCentral - RingCentral is the leading provider of cloud-based communications and collaboration solutions for small business and enterprise companies
Mitel - Business Communications and Collaboration
Dialpad - Switch is a cloud-based phone system built for Google Apps users.
Google Voice - Google Voice gives you one number for all your phones, voicemail organized in an email format, free...
Aircall - Aircall is a call center software of a new generation designed for fast growing companies. Setup instantly and integrates to your CRMs
XO Hosted PBX - Hosted PBX is a scalable UC solution that uses cloud technology to integrate HD voice & data services, mobility, along with advanced calling