Examine source code of Pin Pad Basic Fun

{
  "manifest_version": 2,
  "name": "Pin Pad Basic Fun",
  "version": "1.0",
  "description": "Here, we have provided a numeric keypad/PIN pad through which the user can input the PIN. Once the user enters a PIN and hits “OK”, the code validates the PIN and provides an alert on whether the PIN is correct or not.",
  "permissions": [],
  "browser_action": {
    "default_popup": "game.html",
    "default_icon": {
      "128": "images/pin-logo.png"
    }
  },
  "icons": {
    "128": "images/pin-logo.png"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{8ae8f34a-8ed9-4871-824b-f06bf80f0bc1}"
    }
  }
}