[REST API testing] Isn't there a clever and breakthrough developer out there on Mozilla community ready to provide a kind of disruptive plugin?

Isn’t there a clever developer out there who could design and code a fairly complete and locally used REST API tester plugin? (to finally get rid of Po**man…)
Indeed, seems no big deal to provide some key functionality in a REST client plugin. I’m really annoyed by the poor offering of such plugins in Mozilla browsers in comparison to the native Chrome ones…
Please don’t hesitate to give me your feedback…