I have 1 old 3g, 2 old 3gs, and 2 IPhone 4 collecting dust. Anybody use any of these with the app? I use a 4S now but was the 4 good enough for this? It would be good to use it as a dedicated screen. I mean, it is just going to waste in a box. I use the earlier ones for internet radio around the house. They are on docks connected to Radios and amps.