With his application, Pepper goes towards people to talk to them, and returns home when nobody is around, with a choice of three possible ways to define the home point (Pepper's charging station, a dedicated ARUCO marker, and Pepper's built in SLAM).
To learn more, see the the user guide (pdf).
Using the ARUCO-based localization system requires printing out a special marker with precise codes and dimensions; see this template (Adobe Illustrator format).
Here is an example design:
This marker should be printed in linoleum with 2mm thickness max or as a vinyl sticker