HubSpot CRM - Free CRM software for small businesses.
6sense - 6sense is a B2B predictive intelligence engine for marketing and sales.
Less Annoying CRM - A simple customer relationship manager made just for small businesses. Manage contact info, track leads, and never miss a follow-up.
Leadiro - Seriously Smart & Live B2B Data
Keap - Grow Sales. Save Time. Get Organized.
ZoomInfo - ZoomInfo is a B2B database providing detailed business information on people and companies.