Typeform - Create beautiful, next-generation online forms with Typeform, the form & survey builder that makes asking questions easy & human on any device. Try it FREE!
BuiltWith - Find out the technology behind websites
Tally.so - The simplest way to create forms, for free.
Wappalyzer - Wappalyzer is a technology profilers and leads data provider. Create lists of websites and contacts that use certain technologies.
Paperform - A digital Swiss Army Knife for Small Businesses
What CMS - WhatCMS.org looks at a variety of factors within a webpage to determine what CMS a website is using.