Uptime Kuma is an easy-to-use self-hosted monitoring tool.

Browser and Mobile Automation Test Framework for Node.js

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

Requestly is an open-source tool that simplifies API development, testing, mocking, and integration for developers and QAs.

RapidAPI for Mac is a full-featured HTTP client that lets you test and describe the APIs you build or consume. It has a beautiful native macOS interface to compose requests, inspect server responses, generate client code and export API definitions.

Swagger UI allows anyone — be it your development team or your end consumers — to visualize and interact with the API’s resources without having any of the implementation logic in place