Callpage - Turn website visitors into sales calls. Use CallPage and provide immediate free phone callback to your leads in 28 seconds.
RingCentral - RingCentral is the leading provider of cloud-based communications and collaboration solutions for small business and enterprise companies
Upcall - Upcall enables you to crowdsource your outbound calls. Collaborate with 1000+ on-demand callers worldwide for sales, marketing and customer support calls. Free trial.
Dialpad - Switch is a cloud-based phone system built for Google Apps users.
HeyHi.sg - Video call with interactive whiteboard
Aircall - Aircall is a call center software of a new generation designed for fast growing companies. Setup instantly and integrates to your CRMs