Selenium - Selenium automates browsers. That's it! What you do with that power is entirely up to you. Primarily, it is for automating web applications for testing purposes, but is certainly not limited to just that.
LambdaTest - Perform Web Testing on 2000+ Browsers & OS
TestComplete - TestComplete Desktop, Web, and Mobile helps you create repeatable and accurate automated tests across multiple devices, platforms, and environments easily and quickly.
NextUX Visual Editor - Easy-to-use iteration app for non-designers
Katalon - Built on the top of Selenium and Appium, Katalon Studio is a free and powerful automated testing tool for web testing, mobile testing, and API testing.
Polish - Turn browser into a powerful writing tool, for UX writers