Examine source code of SpeedZ

{
  "manifest_version": 2,
  "name": "SpeedZ",
  "version": "1.3",
  "description": "Adjusts video playback speed",
  "permissions": [
    "activeTab"
  ],
  "content_scripts": [
    {
      "matches": [
        "<all_urls>"
      ],
      "js": [
        "content.js"
      ]
    }
  ],
  "browser_action": {
    "default_popup": "popup.html"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{e9e049c9-c6cf-4547-8d3d-1d3f16d527c6}"
    }
  }
}