Xamarin is one of the solutions to it which actually is meant for cross-platform mobile app development where you can build Android, iOS, and Windows native application using a single codebase. This single platform is C#. The apps developed using Xamarin performs almost similar to the native Platform applications.
Xamarin supports wearable devices as well such as Android Wearand Apple Watch. The functionalities of these wearable devices in their native applications can be incorporated via downloading simple plugins from the Xamarin Component Store.
Popular plugins are cross-platform such as Text-to-Speech and Battery Status. Platform Specific plugins too are available in Xamarin Component store such as the Google Play billing support plugin.
The Xamarin based cross-platform applications can be easily integrated to most of the popular backend platforms such as Parse, Microsoft Azure.
Application indexing in Xamarin allows those applications to be in the search results which usually gets forgotten after few uses from the Users.