Get Leads - Curated directory of 100+ websites to get freelance work.
Wappalyzer - Wappalyzer is a technology profilers and leads data provider. Create lists of websites and contacts that use certain technologies.
B2B SaaS Leads - Get a list of potential customers for your SaaS in 60 secs
BuiltWith - Find out the technology behind websites
Conrati - A virtual consulting marketplace - search, book, consult
What CMS - WhatCMS.org looks at a variety of factors within a webpage to determine what CMS a website is using.