Examine source code of URL List Builder

{
  "manifest_version": 2,
  "name": "URL List Builder",
  "author": "Shakil Ahmed",
  "version": "1.0",
  "permissions": [
    "activeTab"
  ],
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "browser_action": {
    "default_icon": "icon.png",
    "default_popup": "popup.html"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{47a5c585-f2c9-4594-997a-f0c742089b9e}"
    }
  }
}