Examine source code of Tab Refresher Lite

{
  "manifest_version": 2,
  "name": "Tab Refresher Lite",
  "version": "1.0",
  "description": "Auto-refresh the current tab at custom time intervals.",
  "permissions": [
    "tabs"
  ],
  "browser_action": {
    "default_popup": "popup.html",
    "default_icon": {
      "48": "icon.png"
    }
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{1f988549-7394-4c59-90e5-939b82324701}"
    }
  }
}