Examine source code of YouTube Notificator

{
  "manifest_version": 2,
  "author": "Adam 'KaLoSZyFeR' Bozek",
  "name": "YouTube Notificator",
  "version": "0.3resigned1",
  "description": "Adds notifications about switching videos on YouTube tab when you're busy. For example, you play a playlist with YT music, hide the browser and take care of something else. Music switches and you receive a notification with the title of new song.",
  "icons": {
    "48": "icons/ytnotificator-48.png"
  },
  "permissions": [
    "notifications",
    "tabs"
  ],
  "applications": {
    "gecko": {
      "id": "ytnotificator@ytnotificator.com"
    }
  },
  "background": {
    "scripts": [
      "ytntfr-background.js"
    ]
  }
}