Examine source code of jutsu_helper

{
  "name": "jutsu_helper",
  "version": "0.1.0",
  "description": "Free auto skipped intro",
  "author": "hacso",
  "manifest_version": 2,
  "icons": {
    "48": "un.png"
  },
  "browser_action": {
    "default_icon": {
      "19": "un.png",
      "38": "un.png"
    },
    "default_title": "free opening skiper",
    "default_popup": "popup.html"
  },
  "content_scripts": [
    {
      "matches": [
        "*://jut.su/*"
      ],
      "js": [
        "button.js"
      ],
      "run_at": "document_end"
    }
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "{0d0e545d-3162-429d-95dd-28f430ffaefc}"
    }
  }
}