Examine source code of DelayWebpage

{
  "manifest_version": 2,
  "name": "DelayWebpage",
  "version": "1.9223",
  "description": "Sets a delay to distracting websites to help you browse more mindfully",
  "icons": {
    "512": "icon.png"
  },
  "content_scripts": [
    {
      "matches": [
        "<all_urls>"
      ],
      "js": [
        "delay.js"
      ],
      "run_at": "document_start"
    }
  ],
  "options_ui": {
    "page": "options.html"
  },
  "permissions": [
    "storage"
  ],
  "applications": {
    "gecko": {
      "id": "{d08be0ef-4964-48c9-b6a8-6918e05c6f89}"
    }
  }
}