Examine source code of StartupApps

{
  "description": "Open a list of URL at startup in new pinned tabs. (Pinned home pages)",
  "manifest_version": 2,
  "name": "Startup Apps",
  "version": "2.1resigned1",
  "applications": {
    "gecko": {
      "id": "jid0-TgBNh976zF55Pb4ABiM1DXsJV4Q@jetpack",
      "strict_min_version": "45.0"
    }
  },
  "homepage_url": "https://addons.mozilla.org/fr/firefox/addon/startupapps/?src=api",
  "icons": {
    "48": "icons/startup-apps.svg",
    "96": "icons/startup-apps.svg"
  },
  "options_ui": {
    "page": "options/options.html",
    "open_in_tab": false,
    "browser_style": true
  },
  "permissions": [
    "storage",
    "tabs"
  ],
  "background": {
    "scripts": [
      "startup-apps.js"
    ]
  }
}