I would support Polar iWL heartrate monitor if someone releases the specification for the bluetooth protocol they use. Currently i can parse heart rate from that data but there are still many things unclear, like does the belt need some kind of wakeup signal every now and then and when connecting the belt with device etc. I have asked SportsTracker/Polar to open the protocol but no answer yet. I am not sure if its even legal to use their belt with other applications than SportsTracker especially if we have to reverse engineer their protocol...