Callpage - Turn website visitors into sales calls. Use CallPage and provide immediate free phone callback to your leads in 28 seconds.
Clearbit - Clearbit provides Business Intelligence APIs
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.
ZoomInfo - ZoomInfo is a B2B database providing detailed business information on people and companies.
HeyHi.sg - Video call with interactive whiteboard
InsideView - InsideView aggregates and curates all the company and contact data, news and social insights, and professional connections you need to do business better.