Examine source code of Scrypter

{
  "manifest_version": 2,
  "name": "Scrypter",
  "version": "1.0",
  "description": "Injects your JS scripts into any page.",
  "icons": {
    "16": "favicon-16x16.png",
    "32": "favicon-32x32.png",
    "194": "favicon-194x194.png"
  },
  "permissions": [
    "<all_urls>",
    "storage",
    "activeTab",
    "tabs"
  ],
  "browser_action": {
    "default_icon": "favicon-194x194.png",
    "default_title": "Scrypter"
  },
  "background": {
    "scripts": [
      "background.js"
    ],
    "persistent": false
  },
  "options_ui": {
    "page": "index.html",
    "open_in_tab": true
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{35095825-6c70-4bf4-829e-f164151689b0}"
    }
  }
}