Never on my iphone 5s (ios 8.3) - and Half the time it thinks its a headset. Rately on my ipad mini 2 -(ios8.1.2) - and you have to switch back between Bluetooth settings in the app. Even then very rarely picks up a heart rate, I even tried electrical conductivity gel instead of water. -- also to be of any real you so you need to pay a monthly fee, better off paying the extra money for a better device -- perhaps when it is in heaven comfortable strap, maybe one that actually gives you your blood pressures as well, or sleep data.