Examine source code of Fraction Calculator

{
  "manifest_version": 2,
  "name": "Fraction Calculator",
  "version": "1.0",
  "description": "A Mozilla Addon for performing fractional calculations.",
  "icons": {
    "48": "icon.png"
  },
  "browser_action": {
    "default_popup": "popup.html"
  },
  "permissions": [
    "activeTab"
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "{03320d52-ecef-401a-aaf6-60b7e428306f}"
    }
  }
}