Examine source code of cronTab

{
  "manifest_version": 2,
  "name": "cronTab",
  "version": "1.0.1resigned1",
  "description": "Open the specified URL periodically.",
  "icons": {
    "48": "icons/cronTab-48.png",
    "96": "icons/cronTab-96.png",
    "192": "icons/cronTab-192.png"
  },
  "permissions": [
    "storage",
    "alarms",
    "tabs"
  ],
  "browser_action": {
    "default_icon": {
      "16": "icons/cronTab-16.png",
      "32": "icons/cronTab-32.png"
    },
    "default_title": "cronTab",
    "default_popup": "options.html"
  },
  "options_ui": {
    "page": "options.html"
  },
  "background": {
    "scripts": [
      "cron.js",
      "util.js",
      "background.js"
    ]
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{50303c29-40ed-44e3-b3c0-9eb8fae35dd1}"
    }
  }
}