Examine source code of CalendarCost

{
  "manifest_version": 2,
  "name": "CalendarCost",
  "version": "1.0.0",
  "description": "See what your meetings actually cost — in real-time",
  "icons": {
    "16": "icon-16.png",
    "48": "icon-48.png",
    "128": "icon-128.png"
  },
  "permissions": [
    "storage"
  ],
  "content_scripts": [
    {
      "matches": [
        "https://meet.google.com/*-*-*"
      ],
      "js": [
        "content.js"
      ],
      "run_at": "document_idle"
    }
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "calendarcost@calendarcost.com",
      "strict_min_version": "109.0"
    }
  }
}