Examine source code of Tip Calculator Plus

{
  "manifest_version": 2,
  "name": "Tip Calculator Plus",
  "version": "1.1",
  "description": "Calculates tip based on the total bill amount with advanced features",
  "permissions": [
    "activeTab",
    "storage"
  ],
  "browser_action": {
    "default_icon": "icon.png",
    "default_popup": "popup.html"
  },
  "icons": {
    "48": "icon.png"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{77bc6a30-8611-456f-9699-046b1c210628}"
    }
  }
}