For more information about Nod or to contribute to the author, see here
This is a slightly modified version of the Nod Chrome Extension which makes it compatible with Firefox. I am unaffiliated with the author of the original extension. Mozilla code review requires unminified code which is not available to me, thus this cannot be published to the Mozilla addon store.
Click the green button that says "Code" and then "Download ZIP".
Click the blue downloads icon to the right of the url bar and click Nod-for-Firefox-master. Right click Nod-for-Firefox-Master in the popup and select Extract. Click extract.
Navigate to about:debugging and click "Load Temporary Add-On". Select the folder Nod-for-Firefox-master then the file manifest.json.
Navigate here. Sign in/create an account if necessary. Use a real email address, it will be needed later. Click "Submit a New Add-On". Select "On Your Own" then choose the file Nod-for-Firefox.xpi . Click sign.