LinkedIn Sales Navigator - Sales tool for LinkedIn users.
Datanyze - The sales prospecting tool powered by technology data
Gainful.io - Capture B2B leads on AngelList, CrunchBase and LinkedIn
Clearbit Connect - Clearbit Connect is a free extension that surfaces actionable information on the people who email you.
Clearbit - Clearbit provides Business Intelligence APIs
InsideView - InsideView aggregates and curates all the company and contact data, news and social insights, and professional connections you need to do business better.