Examine source code of TurboScan

{
  "manifest_version": 2,
  "name": "TurboScan",
  "version": "2.0",
  "description": "Automatically focuses and selects search inputs on Amazon & eBay for barcode scanning.",
  "permissions": [
    "activeTab"
  ],
  "content_scripts": [
    {
      "matches": [
        "*://www.amazon.com/*",
        "*://www.ebay.com/*"
      ],
      "js": [
        "main.js"
      ],
      "run_at": "document_end"
    }
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "turboscan@localhost"
    }
  }
}