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.

Professional software tool for HTTP testing and debugging

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

Monitor network requests and API failures with real-time insights

Fully integrated API and web service testing capabilities that automate end-to-end functional API testing.

A modern, resource-friendly REST client for Windows 10