Mac CLi - OS X command line tools for developers
Proxyman.io - Proxyman is a high-performance macOS app, which enables developers to view HTTP/HTTPS requests from apps and domains.
Phunt - Product Hunt command line interface
Endpoints - View and respond to requests on an HTTP endpoint
speedtest-cli - Test your download speed using SpeedTest on the command-line
httpbin(1) - HTTP request and response service