Prefer native apps over PWA (#27254)

app/serializers/manifest_serializer.rb

@@ -8,7 +8,8 @@ class ManifestSerializer < ActiveModel::Serializer
   attributes :id, :name, :short_name,
              :icons, :theme_color, :background_color,
              :display, :start_url, :scope,
-             :share_target, :shortcuts
+             :share_target, :shortcuts,
+             :prefer_related_applications, :related_applications
 
   def id
     # This is set to `/home` because that was the old value of `start_url` and
@@ -89,4 +90,28 @@ class ManifestSerializer < ActiveModel::Serializer
       },
     ]
   end
+
+  def prefer_related_applications
+    true
+  end
+
+  def related_applications
+    [
+      {
+        platform: 'play',
+        url: 'https://play.google.com/store/apps/details?id=org.joinmastodon.android',
+        id: 'org.joinmastodon.android',
+      },
+      {
+        platform: 'itunes',
+        url: 'https://apps.apple.com/us/app/mastodon-for-iphone/id1571998974',
+        id: 'id1571998974',
+      },
+      {
+        platform: 'f-droid',
+        url: 'https://f-droid.org/en/packages/org.joinmastodon.android/',
+        id: 'org.joinmastodon.android',
+      },
+    ]
+  end
 end