just a small update on this and a huge thanks to the other people who have written the code needed. I have just hacked about with it and they are no comments on what I have done. but it might set someone on the correct path.
2 device types are for bistable and momentary. then create to virtual on/off devices and link them together with the app.
at the moment the switch states are polled but I would like to get it to the point where it an instantaneous update