From https://once.com/writebook

app/views/pwa/manifest.json.erb

@@ -0,0 +1,42 @@
+{
+  "name": "Writebook",
+  "icons": [
+    {
+      "src": "/app-icon-192.png",
+      "type": "image/png",
+      "sizes": "192x192"
+    },
+    {
+      "src": "/app-icon.png",
+      "type": "image/png",
+      "sizes": "512x512"
+    },
+    {
+      "src": "/app-icon.png",
+      "type": "image/png",
+      "sizes": "512x512",
+      "purpose": "maskable"
+    }
+  ],
+  "start_url": "/",
+  "display": "standalone",
+  "scope": "/",
+  "description": "Writebook is remarkably simple software that allows you to publish text and pictures in a simple, browsable online book format.",
+  "categories": ["books", "business", "productivity"],
+  "shortcuts": [
+    {
+      "name": "Create a new book",
+      "description": "Open Writebook and start writing",
+      "url": "/books/new",
+      "icons": [{ "src": "<%= image_url("add.svg") %>", "sizes": "any" }]
+    },
+    {
+      "name": "Open library",
+      "description": "Open Writebook and see all your books",
+      "url": "/books",
+      "icons": [{ "src": "<%= image_url("books.svg") %>", "sizes": "any" }]
+    }
+  ],
+  "theme_color": "#ffffff",
+  "background_color": "#ffffff"
+}

app/views/pwa/service-worker.js

@@ -0,0 +1,26 @@
+// Add a service worker for processing Web Push notifications:
+//
+// self.addEventListener("push", async (event) => {
+//   const { title, options } = await event.data.json()
+//   event.waitUntil(self.registration.showNotification(title, options))
+// })
+// 
+// self.addEventListener("notificationclick", function(event) {
+//   event.notification.close()
+//   event.waitUntil(
+//     clients.matchAll({ type: "window" }).then((clientList) => {
+//       for (let i = 0; i < clientList.length; i++) {
+//         let client = clientList[i]
+//         let clientPath = (new URL(client.url)).pathname
+// 
+//         if (clientPath == event.notification.data.path && "focus" in client) {
+//           return client.focus()
+//         }
+//       }
+// 
+//       if (clients.openWindow) {
+//         return clients.openWindow(event.notification.data.path)
+//       }
+//     })
+//   )
+// })