TCPView - TCPView is a Windows program that will show you detailed listings of all TCP and UDP endpoints on...
Charles Proxy - HTTP proxy / HTTP monitor / Reverse Proxy
TcpView For Linux - TcpView For Linux. Touch screen friendly design graphical network connections viewer for Linux.
Wireshark - Wireshark is a network protocol analyzer for Unix and Windows. It lets you capture and interactively browse the traffic running on a computer network.
NetStat Agent - At whatever point you open a site association through your program or download documents, you are opening TCP/UDP connions.
Postman - The Collaboration Platform for API Development