LinkedIn - LinkedIn is a business-oriented social networking service, mainly used for professional networking.
ContactRescue - Magically get your address book up-to-date and accurate
Good.Co - eHarmony meets LinkedIn!
Wall Of Me - Wall of me: all your favorite socials in a single place.
indeed - Find jobs using Indeed, the most comprehensive search engine for jobs.
Clearbit Connect - Clearbit Connect is a free extension that surfaces actionable information on the people who email you.