This version of HYDROlink is used to measure the pressure of the connected OIL pump and the temperature of the same OIL. It connects to a device using some sort of a cable with custom jacks.
I don't think it's the same app since this one is developed by Hydrotechnik GmbH, Limburg. Plus, this version installs only on the Windows operating system.
The app you search of is found on this page at the Ecowater Systems.