While more than one person can use Keyto, it is recommended that each person have his or her own device. One important feature of the Keyto App is the ability to follow the long-term trends in both your weight and Keyto Levels. The graph at the bottom of the Journey tab plots your Keyto score against weight so you can see how higher or lower Keyto levels affect your weight. In addition, you can add notes to individual Keyto measurements for later reference, which can be very helpful.
For instance, if you start exercising and notice your levels go up, you can make an annotation to your score. If two people use the device regularly, it is difficult to establish useful trends in data. For that reason, it is best practice for each person to have their own device.