Examine source code of Crunchyroll Sync Tool

{
  "manifest_version": 2,
  "name": "Crunchyroll Sync Tool",
  "version": "1.0",
  "description": "Synchronize two Crunchyroll videos for mixed dubbing and subtitles.",
  "permissions": [
    "activeTab"
  ],
  "content_scripts": [
    {
      "matches": [
        "*://*.crunchyroll.com/*"
      ],
      "js": [
        "popup.js"
      ]
    }
  ],
  "browser_action": {
    "default_popup": "popup.html",
    "default_icon": "icon.png"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{26fd69f0-44ae-4ea8-8ba0-1d33ba39e702}"
    }
  }
}