Apidog

James

Web Debugging Proxy Application

mitmproxy

Intercept network traffic on the fly

Charles

HTTP proxy / HTTP monitor / Reverse Proxy that enables a developer to view all of the HTTP and SSL / HTTPS traffic between their machine and the Internet

wireshark

Wireshark is a free and open-source packet analyzer. It is used for network troubleshooting, analysis, software and communications protocol development, and education. Wireshark is very similar to tcpdump, but has a graphical front-end, plus some integrated sorting and filtering options