Examine source code of Get CRX Ported

{
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "description": "Get source .crx extension file of any Chrome extension",
  "icons": {
    "48": "icon_48.png",
    "128": "icon_128.png"
  },
  "manifest_version": 2,
  "name": "Get CRX",
  "permissions": [
    "https://chrome.google.com/webstore/detail/",
    "contextMenus",
    "downloads"
  ],
  "version": "1.41",
  "browser_specific_settings": {
    "gecko": {
      "id": "{3c302af0-e131-48ab-8280-3f2e191d43fb}"
    }
  }
}