Examine source code of Audible Backup

{
  "manifest_version": 2,
  "name": "Audible Backup",
  "description": "Download and backup your Audible books",
  "author": "Space Meyer",
  "version": "10",
  "browser_action": {
    "default_icon": {
      "48": "icons/icon.png"
    },
    "default_title": "Audible Backup",
    "default_popup": "popup.html"
  },
  "permissions": [
    "<all_urls>"
  ],
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{c64df573-2fdd-4f75-a38e-eed35bc1a08f}"
    }
  }
}