When you look inside the Stylus prefab, there is another prefab called StylusUI.
When this GameObject is in the Scene, you will get a out-of-the-box working UI Panel to list/connect to Stylus Devices.
If you want to create your own UI, have a look inside Holo-Light/STK/Core/Connection/StylusUI.cs. There you can see how it is made.
Basically you just need a reference to HoloStylusManager which exists only on the Stylus GameObject. There you can register for different types of events to handle your UI.
- StartSearchEvent
- DeviceFoundEvent
- DeviceSearchCompleteEvent
- ConnectingStarted
- OnStylusReady
- ConnectionTimeoutEvent
...just to name a few.
If you don't want the default UI, and want your customized version, just remove the StylusUI from your Scene.