The first one worked fine for about 2 weeks until it was removed to move the battery, after which it would not reconnect. You could see it in Bluetooth devices list but didn't communicate with BM2 app. I returned it and got a second one, worked a day, never turned it off, but it's the same with this one. Uninstalled/reinstalled app, cleared storage, restarted phone, uninstalled all other Bluetooth devices, unplugged/plugged monitor, nothing.