Examine source code of SubNet Calc for Android

{
  "name": "SubNet Calc for Android",
  "version": "1.0",
  "description": "A Firefox add-on for calculating IPv4 subnets on Android. Computes network addresses, broadcast addresses, host ranges, and usable hosts using ipaddr.js.",
  "permissions": [],
  "browser_action": {
    "default_title": "SubNet Calc",
    "default_popup": "popup.html"
  },
  "manifest_version": 2,
  "browser_specific_settings": {
    "gecko": {
      "id": "{1022fb38-6e91-4bab-9357-f85d3c9afca7}"
    }
  }
}