Examine source code of Calculator v2

{
  "manifest_version": 2,
  "name": "Calculator",
  "version": "1.0",
  "description": "Perform basic arithmetic operations with ease.",
  "browser_action": {
    "default_popup": "popup.html",
    "default_icon": {
      "48": "icon.png"
    }
  },
  "permissions": [],
  "icons": {
    "48": "icon.png"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{26ba8af0-3aa7-4e80-add8-7e21ef7a8c85}"
    }
  }
}