VirusTotal - VirusTotal is a free service that analyzes suspicious files and URLs and facilitates the quick...
SalesOptimize - Selling to online retailers? Revolutionary sales lead generation search engine driven by deep web analytics
Hunter TechLookup - Create lists of websites by technology for free
Rescan.io - Find the technology stack behind any website. Get the lists of websites using any technology.
URLscan.io - urlscan.io is a free service to scan and analyse websites. When a URL is submitted to urlscan.io, an automated process will browse to the URL like a regular user and record the activity that this page navigation creates.
Elucify - A completely free software tool that uses crowdsourced data to find business email addresses