Charles Proxy - HTTP proxy / HTTP monitor / Reverse Proxy
Weer - A HTTP protocol debugger with Chrome DevTools frontend interface
James - James is a HTTP Proxy and Monitor that enables developers to view and intercept requests made from...
Proxyman.io - Proxyman is a high-performance macOS app, which enables developers to view HTTP/HTTPS requests from apps and domains.
HTTP Headers - HTTP Headers allows you to quickly see the HTTP header information for the current URL.
HTTP Toolkit - Beautiful, cross-platform & open-source tools to debug, test & build with HTTP(S). One-click setup for browsers, servers, Android, CLI tools, scripts and more.