REST does look interesting. Tried to give it a go but it's dependant on also installing the "Websecurify" extension (https://chrome.google.com/webstore/detail/websecurify/emclbd...).

Websecurify looks interesting in itself but requires "access to your data on all websites" permission which means doing a load of research into what it's actually doing etc etc which seems like a lot of effort just to try out a rest client.

Best of luck to them though, Postman made by workflow testing API's hugely more efficient so if they manage to improve on that it'll be a great tool.