Toruń, on the Vistula, was granted town rights in 1233. It is the birthplace of Nicolaus Copernicus, born here in 1473. The medieval Old Town, with its Gothic churches and the ruins of the Teutonic Knights' castle, was inscribed on the UNESCO World Heritage List in 1997. We created an informational mobile app to accompany visitors on a walk around Toruń. It suggests what is worth seeing and lets visitors discover the city at their own pace. The app is available in Polish.