Purchased end of Oct 2012 and used it with my Cyclemeter App connected and setup in minutes and all was working fine very pleased but then as you will read with other reviews the HRM stopped working Feb 2013 approx 3 months of use, tried a few things eg replaced battery etc but no joy. Took it back to Apple Store replaced without any fuss impressed with the service from Apple. I hope the replacement will be more reliable and longer lasting.
Worked great for 3 months until it just stopped working. Changed batteries tried connecting to a number of iPhones all with no luck. Works great when it 'works' but presume the transmitter just breaks. Even tried the Wahoo Utility and that can't find it. AVOID!