Examine source code of Simple IP Calculator

{
  "manifest_version": 2,
  "name": "Simple IP Calculator",
  "version": "0.4resigned1",
  "description": "Determine network details based on an ip and a netmask/CIDR",
  "icons": {
    "96": "icons/icn_ipcalc.png"
  },
  "browser_action": {
    "default_icon": {
      "96": "icons/icn_ipcalc.png"
    },
    "default_title": "IP Calculator",
    "default_popup": "popups/ipcalc.html"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{0c97c2c6-bef9-4d99-9c95-a91212cfe720}"
    }
  }
}