Examine source code of Visual Dictionary

{
  "manifest_version": 2,
  "name": "Visual Dictionary",
  "version": "1.0",
  "description": "Show illustrative images alongside vocabulary words.",
  "icons": {
    "48": "icons/icon.png"
  },
  "permissions": [
    "activeTab"
  ],
  "content_scripts": [
    {
      "matches": [
        "<all_urls>"
      ],
      "js": [
        "content.js"
      ],
      "css": [
        "style.css"
      ]
    }
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "{2c0096ef-e2f7-423e-a080-6d4a7b0132a6}"
    }
  }
}