Examine source code of Boxel Rebound

{
  "manifest_version": 3,
  "name": "Boxel Rebound",
  "description": "Play over 50 levels of box-jumping madness! Design and share your own levels.",
  "version": "1.8.0.8",
  "action": {
    "default_popup": "www/index.html",
    "default_title": "Boxel Rebound",
    "default_icon": {
      "16": "www/img/icons/icon16.png",
      "48": "www/img/icons/icon48.png"
    }
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{3e683b9a-7d8b-43a3-a5cc-2a0a26f2b0ba}"
    }
  },
  "permissions": [
    "storage"
  ]
}