Examine source code of Tab URL Exporter

{
  "manifest_version": 2,
  "name": "Tab URL Exporter",
  "author": "Patric Cunha",
  "version": "1.0",
  "description": "Export all tab URLs from current window to a text file",
  "permissions": [
    "tabs",
    "downloads",
    "activeTab"
  ],
  "background": {
    "scripts": [
      "background.js"
    ],
    "persistent": false
  },
  "browser_action": {
    "default_popup": "popup.html",
    "default_title": "Export Tab URLs",
    "default_icon": {
      "16": "icons/icon-16.png",
      "32": "icons/icon-32.png",
      "48": "icons/icon-48.png",
      "128": "icons/icon-128.png"
    }
  },
  "icons": {
    "16": "icons/icon-16.png",
    "32": "icons/icon-32.png",
    "48": "icons/icon-48.png",
    "128": "icons/icon-128.png"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{a447c3d4-3430-43b0-a6a4-ecd606b42785}"
    }
  }
}