Clearbit - Clearbit provides Business Intelligence APIs
RainKing - RainKing is a marketing system that supports sales teams with enterprise leads, customer leads and marketing in the IT sector.
ZoomInfo - ZoomInfo is a B2B database providing detailed business information on people and companies.
LinkedIn Sales Navigator - Sales tool for LinkedIn users.
InsideView - InsideView aggregates and curates all the company and contact data, news and social insights, and professional connections you need to do business better.
17hats - The all-in-one business system for entrepreneurs.