The Mensa App shows the current menu of the cafeteria at Campus Griebnitzsee of the University of Potsdam and Ulf's Café at the Hasso Plattner Institute (HPI).
More locations:
Uni Potsdam Campus Golm
University of Potsdam Campus Griebnitzsee
Uni Potsdam Campus at the new Palais
The data comes from OpenMensa:
http://openmensa.org/