Examine source code of Audiobook Rocket Tools

{
  "manifest_version": 2,
  "name": "Audiobook Rocket Tools",
  "description": "AudiobookRocket extension allows ACX publishers to activate all promo codes found on the current page.",
  "version": "1.0.0.0",
  "permissions": [
    "https://www.acx.com/sales/dashboard/promo"
  ],
  "background": {
    "scripts": [
      "background.js"
    ],
    "persistent": false
  },
  "browser_action": {
    "default_popup": "index.html"
  },
  "icons": {
    "48": "images/abr_icon48.png",
    "128": "images/abr_icon128.png"
  }
}