Examine source code of Square Calculator

{
  "manifest_version": 2,
  "name": "Square Calculator",
  "version": "1.0",
  "description": "Calculates the square of a number.",
  "permissions": [],
  "browser_action": {
    "default_icon": "icon.png",
    "default_popup": "popup.html"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{d7a9bdf7-7102-4d9d-9d59-4c81233d88f4}"
    }
  }
}