Fiddler - Fiddler is a debugging program for websites.
Postman - The Collaboration Platform for API Development
Proxyman.io - Proxyman is a high-performance macOS app, which enables developers to view HTTP/HTTPS requests from apps and domains.
curl.io - Share your files from your Terminal / SSH
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.
TermHere - “Open Terminal Here” shortcut for Finder