BuiltWith - Find out the technology behind websites
Lead Forensics - B2B website analytics and lead generation.
FindThatLead Prospector - Feed your sales team with daily leads.
Hunter - Find all the email addresses related to a domain
Prospect.io - Prospecting, like a boss. Find any email, reach out, measure everything and integrate with your CRM.
SalesOptimize - Selling to online retailers? Revolutionary sales lead generation search engine driven by deep web analytics