Arendo - heart rate belt / heart rate monitor (Heart Rate Monitor) | Chest | Transmitter with Bluetooth Smart 4.0 | waterproof | 14 grams | Black | Apple Products | with App i-gotU Sports on many Android devices (equipment)
Only when connecting with runtastic there were difficulties: You have to be declared as runtastic belt and NOT as other BT4.0 strap the belt. Then the coupling and detection works just fine through the APP. The belt itself is lightweight, flexible and comfortable to wear.