Examine source code of ContinueTube

{
  "manifest_version": 3,
  "name": "ContinueTube",
  "version": "1.0.1",
  "description": "ContinueTube is a Chrome extension that allows you to continue watching a YouTube video on your phone.",
  "icons": {
    "16": "icon.svg",
    "48": "icon.svg",
    "128": "icon.svg"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "continuetube@extension.local"
    }
  },
  "permissions": [],
  "host_permissions": [
    "https://www.youtube.com/*",
    "https://m.youtube.com/*",
    "https://youtu.be/*"
  ],
  "content_scripts": [
    {
      "matches": [
        "https://www.youtube.com/*"
      ],
      "js": [
        "content.js"
      ],
      "css": [
        "content.css"
      ],
      "run_at": "document_idle"
    }
  ]
}