Examine source code of Currency Converter

{
  "manifest_version": 2,
  "name": "Currency Converter",
  "version": "1.0",
  "author": "xtyl",
  "homepage_url": "https://github.com/x1yl",
  "description": "Convert between different currencies using real-time exchange rates.",
  "icons": {
    "16": "icons/icon16.png",
    "24": "icons/icon24.png",
    "32": "icons/icon32.png",
    "64": "icons/icon64.png",
    "128": "icons/icon128.png"
  },
  "browser_action": {
    "default_title": "Currency Converter",
    "default_popup": "popup.html"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{930604f4-7784-4d7c-9c9d-c09509a85b7a}"
    }
  }
}