Just bringing together a few recent posts;

Windows 10–Simple Universal Windows Platform Demo App

Windows 10 IoT Core, UWP and Raspberry Pi 2–The Switched Blinking Light Demo

Windows 10 IoT Core–Network Enabling the Blinking LED Demo with AllJoyn

Windows 10 IoT Core–More Baby Steps with AllJoyn

I brought some of that into one little screencast video of ‘an app’ which does (in a very basic form);

• Code which is both universal and (at times) device-family specific running on desktop, phone and IoT Core
• UI which responds to device changes
• A simple service which advertises itself on AllJoyn
• A simple client which consumes that service

Here’s the video;