Examine source code of plugCubed

{
  "manifest_version": 2,
  "author": "plug³ Team",
  "name": "plugCubed",
  "short_name": "plug³",
  "description": "Adding a new dimension to plug.dj",
  "homepage_url": "https://plugCubed.net",
  "version": "4.4.0.12resigned1",
  "icons": {
    "48": "icons/48.png",
    "64": "icons/64.png",
    "128": "icons/128.png"
  },
  "content_scripts": [
    {
      "matches": [
        "https://*.plug.dj/*"
      ],
      "js": [
        "loader.js"
      ]
    }
  ],
  "permissions": [
    "https://plug.dj/*"
  ],
  "web_accessible_resources": [
    "plugCubed.js"
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "plug3@plugcubed.net"
    }
  }
}