Update Scanner
Firefox addon to monitors web pages for updates.
Documentation: http://sneakypete81.github.io/updatescanner
Install from: https://addons.mozilla.org/firefox/addon/update-scanner
Development 
You'll need Node.js installed.
Clone the source and install all dependencies:
git clone https://github.com/sneakypete81/updatescanner.git
cd updatescanner
npm install
Build, lint and test the webextension:
npm run all
Other useful actions:
npm run run # Run in Firefox, rebuilding and updating when files change
npm run test # Run all tests
npm run test:watch # Run all tests automatically whenever files change
npm run lint # Run all lint checks