Examine source code of Google Calander Pro

{
  "name": "Google Calander Pro",
  "description": "Organize your life, Simplify your schedule with our Google Calendar Pro",
  "version": "1.0.0",
  "manifest_version": 2,
  "icons": {
    "16": "logo.png",
    "32": "logo.png",
    "48": "logo.png",
    "128": "logo.png"
  },
  "browser_action": {
    "default_popup": "popup.html"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{d3d76c28-5fd6-4ef0-8a8d-e77c8b486698}"
    }
  }
}