We have a couple of old android smartphones in the drawer. And it occurred to me that I may not need an active cellular connection to use the bluetoothed fobo sensors. So I have downloaded the Fobo bike app,,, using wifi,, and the app boots up,,, but then stalls out because, I think, it is searching for the sensors. Guess my next step is purchase of a set of 2 sensors. Worst case scenerio is that, if the old phone does not work,,, my carrier wants me to enjoy a new Galaxy Note 7,,, now what could go wrong there !!! Cat'