Wappalyzer - Wappalyzer is a technology profilers and leads data provider. Create lists of websites and contacts that use certain technologies.
SE Ranking - All-in-One cloud-based SEO software for agencies, marketing teams and webmasters
BuiltWith - Find out the technology behind websites
DeskAlerts - Send alerts to any corporate device: PCs, phones, tablets, etc.
What CMS - WhatCMS.org looks at a variety of factors within a webpage to determine what CMS a website is using.
SEMRush - All-in-one Marketing Toolkit for digital marketing professionals.