Examine source code of Youtube Visualize Player

{
  "manifest_version": 2,
  "name": "Youtube Visualize Player",
  "version": "1.0.3resigned1",
  "description": "A firefox plugin for youtube that make visualize spectrum during playing",
  "icons": {
    "48": "icons/icon-48.png"
  },
  "content_scripts": [
    {
      "matches": [
        "*://*.youtube.com/*"
      ],
      "js": [
        "index.js"
      ]
    }
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "{ea3021d1-3e9a-48db-af8e-be866114d4ed}"
    }
  }
}