As a developer I sometimes need to be able to make GET/POST requests without having a form on the page. Are there any plug-ins that allow me to submit GET/POST requests to a specified page and then see the results?
Simple REST Client. No frills, gets the job done.
You can try POSTMAN.
It works good for making HTTP requests and debugging and I like its UI.
"REST & HTTP API developer's pocket knife. Easy to use and configurable. HATEOAS, Hypermedia, Requests History+Repository, and more."
I find it very useful and it has many features.
XHR Poster is great, lets you save some requests, and shows the response nicely formatted. The results panel is tabbed so you can see many results after doing new requests.
Spy plugin for Chrome
It shows you all requests on website, allows to edit and send GET,POST,PUT,PATCH requests. You can see a animated promotional page at the Chrome Web Store here.