Examine source code of Tab Auto Sort

{
  "manifest_version": 2,
  "name": "Tab Auto Sort",
  "version": "1.0.1",
  "description": "Move the tabs you last used to either end of the tab list to keep organised.",
  "icons": {
    "48": "icon.svg"
  },
  "background": {
    "scripts": [
      "background-script.js"
    ]
  },
  "permissions": [
    "storage"
  ],
  "options_ui": {
    "page": "settings.html",
    "browser_style": true
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "tabautosort@figgyc.uk"
    }
  }
}