We also had trouble connecting multiple devices but can create multiple profiles on the same device

The app allows you to see your data via a tracking graph for weight and body fat but none of the other measures it also has no way to export the data so not only does it not let you track the other measurements easily it also offers no way of using something else to measure this

In terms of the app it sometimes has trouble connecting to the scales but only had this once or twice otherwise its been fine