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.
Postman - The Collaboration Platform for API Development
TestComplete - TestComplete Desktop, Web, and Mobile helps you create repeatable and accurate automated tests across multiple devices, platforms, and environments easily and quickly.
Sauce Labs - Test mobile or web apps instantly across 700+ browser/OS/device platform combinations - without infrastructure setup.
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.
Ranorex Studio - Accelerate testing with Ranorex Studio, the all-in-one tool for test automation. For desktop, web, or mobile app testing, with easy codeless automation tools, a full IDE, robust object recognition, flexible reporting and built-in Selenium WebDriver.