Examine source code of ServerCheck

{
  "manifest_version": 2,
  "name": "ServerCheck",
  "default_locale": "en",
  "description": "__MSG_description__",
  "version": "1.0.6resigned1",
  "browser_action": {
    "default_icon": "images/icon.png",
    "default_popup": "popup.html"
  },
  "icons": {
    "128": "images/icon_128.png"
  },
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "permissions": [
    "activeTab",
    "storage",
    "alarms",
    "<all_urls>",
    "notifications"
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "{f583e1a4-76ef-4062-b13e-df1437e9c6e3}"
    }
  }
}