Proxyman.io - Proxyman is a high-performance macOS app, which enables developers to view HTTP/HTTPS requests from apps and domains.
Fiddler - Fiddler is a debugging program for websites.
Ray - The super remote that changes your TV forever
Surge for Mac - Advanced Web Debugging Proxy for Mac & iOS
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.
RegExr - RegExr.com is an online tool to learn, build, and test Regular Expressions.