I've met these products mostly in the context of front-end engineers needing endpoints that don't exist yet.

Useful for QA testers too.

Yeah they look quite simular.

Yeah I'm not sure I would use it for automated tests, you kind of want something abit more "robust" for those tests. This tool was designed to help get people off the ground, but I guess there is no reason why you could'nt use it for automated tests etc. Not sure I would!