It is possible to connect the Healy device to only one of these two Apps at the same time on your smartphone. It can’t communicate with both Apps at the same time, just like it can’t be used on two different smartphones at the same time. If your Healy device is already connected to one of these Apps, but you want to connect it to the other one, the App to which it is connected needs to be closed before trying to connect the Healy to the other App.