Examine source code of deyoutube

{
  "manifest_version": 2,
  "name": "Deyoutube",
  "version": "0.12",
  "description": "Kill addiction to Youtube Feed",
  "icons": {
    "48": "icons/logo-48.png"
  },
  "content_scripts": [
    {
      "matches": [
        "*://*.youtube.com/*"
      ],
      "js": [
        "deyoutube.js"
      ]
    }
  ]
}