ContactRescue - Magically get your address book up-to-date and accurate
Clearbit - Clearbit provides Business Intelligence APIs
Wall Of Me - Wall of me: all your favorite socials in a single place.
ZoomInfo - ZoomInfo is a B2B database providing detailed business information on people and companies.
Clearbit Connect - Clearbit Connect is a free extension that surfaces actionable information on the people who email you.
DiscoverOrg - DiscoverOrg is an IT sales intelligence platform providing technology marketers access to data, IT org charts, and real time projects.