“…Uddin et al,in [7,8], describe in detail how to use smartphones to plot automatic flow paths, also explaining the system architecture, data acquisition, data fusion, accuracy, and functioning of the methodology. To implement a similar approach, it is also possible to rely on commercially available apps such as the one described in [32]. Again, readers are invited to consult [32] to obtain information about the system architecture, the accuracy of the approach, and its functioning.…”