Examine source code of Auto Refresh Addon

{
  "manifest_version": 2,
  "name": "Auto Refresh Addon",
  "version": "1.0",
  "description": "Automatically refreshes the page at a set interval.",
  "permissions": [
    "tabs",
    "activeTab",
    "scripting"
  ],
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "browser_action": {
    "default_popup": "popup.html"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{4a1d5576-fe1b-469a-bf28-237d16bc7e5f}"
    }
  }
}