Examine source code of Devscan

{
  "manifest_version": 2,
  "name": "Devscan",
  "version": "1.0.1",
  "description": "Scan meta/css/js + headers + robots/sitemaps + detect API/RSS/XML. Save HTML + export CSV.",
  "browser_specific_settings": {
    "gecko": {
      "id": "devscan@networkluki.com",
      "strict_min_version": "140.0",
      "data_collection_permissions": {
        "required": [
          "none"
        ]
      }
    },
    "gecko_android": {
      "strict_min_version": "142.0"
    }
  },
  "browser_action": {
    "default_title": "Devscan",
    "default_popup": "popup.html"
  },
  "permissions": [
    "activeTab",
    "downloads",
    "<all_urls>"
  ],
  "background": {
    "scripts": [
      "background.js"
    ]
  }
}