Examine source code of uTube

{
  "name": "uTube",
  "description": "Show an embedded video on a simple blank page when visiting a YouTube video link.",
  "version": "1.5",
  "manifest_version": 2,
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "content_scripts": [
    {
      "matches": [
        "https://utube.realityripple.com/"
      ],
      "js": [
        "content.js"
      ]
    },
    {
      "matches": [
        "https://www.youtube.com/embed/*",
        "https://www.youtube-nocookie.com/embed/*"
      ],
      "js": [
        "embed.js"
      ],
      "all_frames": true
    }
  ],
  "permissions": [
    "webRequest",
    "*://www.youtube.com/*",
    "*://m.youtube.com/*",
    "webRequestBlocking",
    "storage"
  ],
  "options_ui": {
    "page": "options.html",
    "open_in_tab": false
  },
  "icons": {
    "64": "icon.png"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{c3516bde-761e-4e70-94f3-38acb06274b8}"
    }
  }
}