Examine source code of Automatic Tab Refresher

{
  "manifest_version": 2,
  "name": "Auto Refresh",
  "version": "1.2",
  "description": "Auto refresh active tab with selectable intervals.",
  "permissions": [
    "tabs",
    "activeTab"
  ],
  "icons": {
    "128": "icon.png"
  },
  "background": {
    "scripts": [
      "background.js"
    ],
    "persistent": true
  },
  "browser_action": {
    "default_icon": "icon.png",
    "default_popup": "popup.html",
    "default_title": "Auto Refresh"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{1cd26739-7d9e-4433-83ee-27c96238200e}"
    }
  }
}