Postman is an API platform for building and using APIs. Postman simplifies each step of the API lifecycle and streamlines collaboration so you can create better APIs—faster.

Streamline your API testing, integration testing and test data management.

Browser and Mobile Automation Test Framework for Node.js

Monitor network requests and API failures with real-time insights

Hand-crafted lightweight Rest Client for testing APIs. Supports collections, environments, git collaboration and local storage.

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.