diff --git a/src/service-worker.js b/src/service-worker.js
index f9d21007..a4353814 100644
--- a/src/service-worker.js
+++ b/src/service-worker.js
@@ -19,6 +19,7 @@ const assets = __assets__
   .filter(filename => !filename.endsWith('.map'))
   .filter(filename => filename !== '/robots.txt')
   .filter(filename => !filename.includes('traineddata.gz')) // Tesseract already caches it in IDB
+  .filter(filename => !filename.endsWith('.webapp')) // KaiOS manifest
 
 // `shell` is an array of all the files generated by webpack
 // also contains '/index.html' for some reason
diff --git a/static/manifest.webapp b/static/manifest.webapp
new file mode 100644
index 00000000..4fff47e3
--- /dev/null
+++ b/static/manifest.webapp
@@ -0,0 +1,37 @@
+{
+  "version": "1.0.0",
+  "name": "Pinafore",
+  "description": "Mastodon client",
+  "type": "web",
+  "launch_path": "/",
+  "icons": {
+    "48": "/icon-48.png",
+    "72": "/icon-72.png",
+    "96": "/icon-96.png"
+  },
+  "developer": {
+    "name": "Nolan Lawson",
+    "url": "https://nolanlawson.com"
+  },
+  "locales": {
+    "en-US": {
+      "name": "Pinafore",
+      "subtitle": "Mastodon client",
+      "description": "Mastodon client, focused on speed and simplicity."
+    }
+  },
+  "default_locale": "en-US",
+  "permissions": {
+    "serviceworker": {
+      "description": "Needed for offline storage and notifications."
+    },
+    "desktop-notification": {
+      "description": "Needed for notifications."
+    }
+  },
+  "messages": [
+    {
+      "serviceworker-notification": "/"
+    }
+  ]
+}