The APP allows the acquisition, management and analysis of flow rates using Windows. The technical basis of the program is provided by the gauging regulation, Annex D. The determination of the flow rate (Q) must be executed applying the surface speed method, which is customary in the hydrological practice. Considering the device-specific parameters, the total flow can be evaluated immediately after the data acquisition. The convenient user interface provides the user with a variety of applications for water analysis. From the available data, vertical velocity profiles and isotachs are calculated and illustrated in graphs. Faulty measurements are thus recognised early on and they can be corrected immediately or discarded. Just one mouse click generates a detailed measurement protocol with the input data of the measurement, the calculation results, the gauging requirement, the velocity profiles of the plumb line and the measuring section. "Pro" Module Features: integrated finite element module, calculation of partial outflows, virtual vertical and horizontal sections, determination of calibration factors