AwesomeDigest - An email newsletter for every "awesome" list on GitHub 😻
BuiltWith - Find out the technology behind websites
DevScreen - Automated, practical interview assessments for developers
Wappalyzer - Wappalyzer is a technology profilers and leads data provider. Create lists of websites and contacts that use certain technologies.
git:logs - The definitive list of open source resources on Github
WhatRuns - Extension that helps you identify technologies used on any website at the click of a button.