Since the app is for Windows Phone 8.1 flavored models only, you will have to wait for Sammy to roll out a firmware update first, followed by the actual Windows Phone 8.1 update. We expect the Samsung ATIV S, Samsung ATIV SE, and the Samsung ATIV S Neo to be recipients of the new Windows Phone build.
If you own one of Samsung's Windows Phone flavored handsets, you should be looking forward to all of the new features that your phone will receive.