Examine source code of YoutubeCinema

{
  "name": "YoutubeCinema",
  "version": "1.3.1resigned1",
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "page_action": {
    "browser_style": true,
    "default_icon": {
      "19": "img/icon_active/19.png",
      "38": "img/icon_active/38.png",
      "48": "img/icon_active/48.png",
      "96": "img/icon_active/96.png",
      "128": "img/icon_active/128.png"
    }
  },
  "permissions": [
    "*://*.youtube.com/*",
    "tabs",
    "webNavigation",
    "webRequest",
    "webRequestBlocking"
  ],
  "icons": {
    "19": "img/icon_active/19.png",
    "38": "img/icon_active/38.png",
    "48": "img/icon_active/48.png",
    "96": "img/icon_active/96.png",
    "128": "img/icon_active/128.png"
  },
  "applications": {
    "gecko": {
      "id": "youtubecinema@youtubecinema"
    }
  },
  "manifest_version": 2
}