RESTer is great, I like it and I am using it for quite a while now. It supports different kinds of authentications and I like how easily it structures the requests in a tree structure on left hand side.

What I do not like is the bug in the EXPORT REQUESTS function... "Ups, something went wrong! e is undefined". Without that function I always have to start configuring my request from scratch after using a different Firefox on any new physical or virtual machine...