core/manifest.json

{
  "short_name": "Harukin+",
  "name": "Harukin+!",
  "icons": [
    {
      "src": "icon.png",
      "type": "image/png",
      "sizes": "192x192"
    }
  ],
  "start_url": "/",
  "background_color": "#fff",
  "theme_color": "#004898",
  "display": "standalone"
}