Examine source code of YouTube Recommender

{
  "manifest_version": 2,
  "name": "YouTube Recommender",
  "version": "1.0",
  "permissions": [
    "tabs",
    "storage",
    "activeTab"
  ],
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "browser_action": {
    "default_popup": "popup.html"
  },
  "applications": {
    "gecko": {
      "id": "topic_recommend@example.com",
      "strict_min_version": "89.0"
    }
  }
}