Examine source code of Better Mobile Youtube

{
  "name": "better-mobile-youtube",
  "version": "0.0.6",
  "manifest_version": 2,
  "description": "Better mobile Youtube aims to provide better feature for mobile youtube on firefox ",
  "icons": {
    "16": "icon.png",
    "128": "icon.png"
  },
  "permissions": [
    "storage"
  ],
  "content_scripts": [
    {
      "matches": [
        "*://m.youtube.com/*"
      ],
      "js": [
        "app.js"
      ],
      "run_at": "document_idle"
    }
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "{2e55a874-68aa-4f27-aef9-8e38982a4a8c}"
    }
  }
}