Examine source code of WebsiteWatcher

{
  "manifest_version": 2,
  "name": "WebsiteWatcher",
  "version": "1.1",
  "description": "Alerts users when specified websites change content or structure",
  "icons": {
    "48": "icons/icon-48.png",
    "96": "icons/icon-96.png"
  },
  "permissions": [
    "<all_urls>",
    "storage",
    "alarms",
    "notifications"
  ],
  "browser_action": {
    "default_icon": "icons/icon-48.png",
    "default_title": "WebsiteWatcher",
    "default_popup": "popup/popup.html"
  },
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "options_ui": {
    "page": "options/options.html"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{57b80ca4-188d-4229-930b-a927587936ec}"
    }
  }
}