Xplain

manifest.json

{
  "update_url": "https://clients2.google.com/service/update2/crx",
  "manifest_version": 3,
  "name": "Xplain",
  "version": "1.0",
  "description": "Accelerate your learning process!",
  "permissions": [
    "activeTab"
  ],
  "action": {
    "default_popup": "index.html"
  },
  "content_scripts": [
    {
      "matches": [
        "*://www.youtube.com/watch?v=*"
      ],
      "js": [
        "content.js"
      ]
    }
  ]
}