Device-specific hardware tends to get overlooked by the third-party development community, but the S Pen from Samsung's Note phones might be the exception. There are a lot of Note users out there and it has a stylus that's actually worth using. Samsung is now offering game developers a way to better utilize that feature with the Unity Extension SDK, which can be downloaded from Samsung's developer site.
In case you're not aware, Unity is a 3D game engine that's used by a number of popular titles. The new SDK will allow developers to accept input from the S Pen. The SDK provides devs with access to SCanvasView in their games.