Examine source code of Simple Calculator Fun

{
  "manifest_version": 2,
  "name": "Simple Calculator Fun",
  "version": "1.0",
  "description": "Simple Calculator. This utility provides an interface to perform basic mathematical operations such as addition, subtraction, multiplication, and division.",
  "permissions": [],
  "browser_action": {
    "default_popup": "game.html",
    "default_icon": {
      "128": "images/calcu-logo.png"
    }
  },
  "icons": {
    "128": "images/calcu-logo.png"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{f7ad737b-8a81-4a6d-870b-2f3964a97217}"
    }
  }
}