Examine source code of QuickSketch

{
  "manifest_version": 2,
  "name": "QuickSketch",
  "version": "1.0",
  "description": "Create and save quick sketches instantly in your browser.",
  "icons": {
    "48": "icon.png"
  },
  "permissions": [],
  "browser_action": {
    "default_icon": "icon.png",
    "default_popup": "popup.html"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{9ed4d5c2-4cec-490c-8d01-0f7ec20588c7}"
    }
  }
}