Postman - The Collaboration Platform for API Development
Charles Proxy - HTTP proxy / HTTP monitor / Reverse Proxy
Insomnia REST - The most intuitive cross-platform REST API Client ð´
RESTer - A REST client for almost any web service (Firefox and Chrome extension).
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.
Postwoman - An online, open source API request builder