Percy is a visual testing and monitoring tool that focuses on detecting visual changes in web applications

Built for developers and testers alike, SoapUI is the only open source tool that covers the entire testing spectrum (functional, security, load, mocking).

Burp or Burp Suite is a set of tools used for penetration testing of web applications. It is developed by a company named Portswigger who make freely available a Web Security Academy which has a range of lessons on penetration testing.

Unifying API testing, API Performance testing, API Mocks and UI testing.

The Complete Continuous Testing Platform Any test. Any device. App quality without limits.

Voiden is a developer-first API client with local storage, Git-integrated, all based on markdown + offline support.