Examine source code of Jelly Party

{
  "name": "Jelly Party",
  "version": "1.7.3",
  "description": "Watch videos with your friends — in sync!",
  "permissions": [
    "activeTab",
    "storage"
  ],
  "optional_permissions": [
    "http://*/*",
    "https://*/*"
  ],
  "background": {
    "scripts": [
      "js/background.js"
    ]
  },
  "browser_action": {
    "default_popup": "popup.html",
    "default_icon": {
      "16": "images/logo/16x16.png",
      "32": "images/logo/32x32.png",
      "48": "images/logo/48x48.png",
      "128": "images/logo/128x128.png"
    }
  },
  "content_scripts": [
    {
      "matches": [
        "https://join.jelly-party.com/*"
      ],
      "js": [
        "js/sidebar.js"
      ]
    }
  ],
  "icons": {
    "16": "images/logo/16x16.png",
    "32": "images/logo/32x32.png",
    "48": "images/logo/48x48.png",
    "128": "images/logo/128x128.png"
  },
  "manifest_version": 2,
  "content_security_policy": "script-src 'self' 'unsafe-eval'; connect-src 'self' http://localhost:8098 ws://localhost:8098 wss://staging.jelly-party.com:8080 wss://ws.jelly-party.com:8080; object-src 'self'",
  "web_accessible_resources": [
    "js/rootStyles.js",
    "iframe.html",
    "join.html"
  ]
}