Charles is a HTTP proxy that enables you to see traffic between your machine and the backend

Mock and modify HTTP request for exploratory testing.

Supercharge team collaboration by sharing screen capture, logs, and debugging information from local development.

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.

Puppeteer is a Node.js library which provides a high-level API to control Chrome/Chromium over the DevTools Protocol.

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