Examine source code of Conversion Unit

{
  "manifest_version": 2,
  "name": "Conversion Unit",
  "version": "1.0",
  "description": "Helps switch between measurement units such as meters, feet, kilograms, pounds, etc.",
  "icons": {
    "48": "icon.png"
  },
  "browser_action": {
    "default_icon": "icon.png",
    "default_popup": "popup.html"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{d46d56e6-8552-4357-954d-e3566bfb3d2f}"
    }
  }
}