tcpdump - tcpdump is a common packet analyzer that runs under the command line.
Postman - The Collaboration Platform for API Development
SmartSniff - SmartSniff is a packet sniffer that capture TCP/IP packets and display them as sequence of conversations between clients and servers.
TablePlus for Windows - A native GUI tool for MySQL, PostgreSQL, SQL Server & more
netcat - Netcat is a featured networking utility which reads and writes data across network connections...
Postman for Mac (Beta) - Build, test, and document your APIs faster