Surge for Mac - Advanced Web Debugging Proxy for Mac & iOS
Weer - A HTTP protocol debugger with Chrome DevTools frontend interface
Charles Proxy - HTTP proxy / HTTP monitor / Reverse Proxy
HTTP Headers - HTTP Headers allows you to quickly see the HTTP header information for the current URL.
Qustodio - Free parental control software. Monitor and track your child's online activity. Block dangerous sites and protect kids from online bullying.
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.