I want to buy the Fischer ECU 1760 and have also dealt with the app a little. I think this is the same app as for the ECU 1723.
From their website:
With our new FISCHER E-Connect APP you can not only navigate FREE of charge on Europe's cycle paths, it also connects to your FISCHER pedelec and shows you various current information about your e-bike.
Unleash your Fischer bike with additional computer functions and navigation