GitHub Codespaces - GItHub Codespaces is a hosted remote coding environment by GitHub based on Visual Studio Codespaces integrated directly for GitHub.

Proxyman.io - Proxyman is a high-performance macOS app, which enables developers to view HTTP/HTTPS requests from apps and domains.

CloudShell - Cloud Shell is a free admin machine with browser-based command-line access for managing your infrastructure and applications on Google Cloud Platform.

httpbin(1) - HTTP request and response service

CodeTasty - CodeTasty is a programming platform for developers in the cloud.

Endpoints - View and respond to requests on an HTTP endpoint