Examine source code of SeekCC

{
  "manifest_version": 2,
  "name": "Seek Subtitles for YouTube",
  "short_name": "Seek Subtitles",
  "author": "J. Rajer",
  "description": "Save time watching youtube videos by filtering their subtitles and skipping uninteresting parts.",
  "version": "1.0.8resigned1",
  "icons": {
    "48": "icon.png",
    "96": "icon96.png"
  },
  "permissions": [
    "webRequest",
    "https://*/*",
    "activeTab",
    "storage"
  ],
  "web_accessible_resources": [
    "js/player.js",
    "index.html",
    "css/close.gif",
    "css/close-dark.gif"
  ],
  "content_scripts": [
    {
      "matches": [
        "https://www.youtube.com/*"
      ],
      "css": [
        "css/jquery.dataTables.min.css",
        "css/jquery-ui.css",
        "css/style.min.css"
      ],
      "js": [
        "js/jquery-3.2.1.min.js",
        "js/jquery-ui.min.js",
        "js/jquery.dataTables.min.js",
        "js/moment.js",
        "js/main.js"
      ]
    }
  ],
  "background": {
    "scripts": [
      "js/background.js"
    ]
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{31d4afa4-6683-46b6-b541-8d8a2650c41e}"
    }
  }
}