diff --git a/keyserver/src/keyserver.js b/keyserver/src/keyserver.js
--- a/keyserver/src/keyserver.js
+++ b/keyserver/src/keyserver.js
@@ -8,6 +8,9 @@
 import os from 'os';
 
 import './cron/cron.js';
+
+import stores from 'lib/facts/stores.js';
+
 import { migrate } from './database/migrations.js';
 import { jsonEndpoints } from './endpoints.js';
 import { emailSubscriptionResponder } from './responders/comm-landing-responders.js';
@@ -120,6 +123,17 @@
         downloadHandler(uploadDownloadResponder),
       );
 
+      // This endpoint should be handled by the mobile app. If the server
+      // receives this request, it means that the app is not installed and we
+      // should redirect the user to a place from which the app can be
+      // downloaded.
+      router.get('/invite/:secret', (req, res) => {
+        res.writeHead(301, {
+          Location: stores.appStoreUrl,
+        });
+        res.end();
+      });
+
       // $FlowFixMe express-ws has side effects that can't be typed
       router.ws('/ws', onConnection);
       router.get('/worker/:worker', webWorkerResponder);
diff --git a/landing/qr.react.js b/landing/qr.react.js
--- a/landing/qr.react.js
+++ b/landing/qr.react.js
@@ -9,6 +9,8 @@
 import { FontAwesomeIcon } from '@fortawesome/react-fontawesome';
 import * as React from 'react';
 
+import stores from 'lib/facts/stores.js';
+
 import css from './qr.css';
 
 function QR(): React.Node {
@@ -32,7 +34,7 @@
         </div>
       </a>
 
-      <a href="https://apps.apple.com/us/app/comm-messenger/id1574433435">
+      <a href={stores.appStoreUrl}>
         <div className={`${css.qr_link} ${css.qr_link_appstore}`}>
           <FontAwesomeIcon icon={faAppStoreIos} size="lg" style={iconStyle} />
           <h3>App Store (pre-alpha)</h3>
diff --git a/lib/facts/stores.js b/lib/facts/stores.js
new file mode 100644
--- /dev/null
+++ b/lib/facts/stores.js
@@ -0,0 +1,7 @@
+// @flow
+
+const stores = {
+  appStoreUrl: 'https://apps.apple.com/us/app/comm-messenger/id1574433435',
+};
+
+export default stores;