Charles Proxy - HTTP proxy / HTTP monitor / Reverse Proxy
HackerOne - HackerOne provides a platform designed to streamline vulnerability coordination and bug bounty program by enlisting hackers.
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.
Intruder - Intruder is a security monitoring platform for internet-facing systems.
Postman - The Collaboration Platform for API Development
Forcepoint Web Security Suite - Internet Security