Examine source code of The Onion Notifier

{
  "name": "The Onion Notifier",
  "version": "0.1.1resigned1",
  "description": "Notify you when you visit a website that offer an .onion domain. Only intended for use with the Tor Browser.",
  "homepage_url": "https://github.com/stefansundin/the-onion-notifier",
  "author": "Stefan Sundin",
  "icons": {
    "16": "img/icon16.png",
    "48": "img/icon48.png",
    "128": "img/icon128.png"
  },
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "options_ui": {
    "page": "options.html",
    "chrome_style": true
  },
  "browser_action": {
    "default_icon": {
      "38": "img/icon38.png"
    },
    "default_popup": "options.html"
  },
  "permissions": [
    "tabs",
    "notifications",
    "storage"
  ],
  "applications": {
    "gecko": {
      "id": "the-tor-notifier@firefox.stefansundin.com"
    }
  },
  "manifest_version": 2
}