The Museum of Post and Telecommunications in Wrocław is the only museum of its kind in Poland. It is housed in a 1929 building on Krasińskiego Street, regarded as Wrocław's first high-rise, which before the war was home to the postal cheque office. Its collection includes late-19th-century mail coaches, postmen's uniforms, post horns, letter boxes, telephone and telegraph equipment, as well as a rich collection of postage stamps. We created a mobile app and an audio guide system that lead visitors through the exhibition and tell how the ways of sending messages changed over the centuries – from mounted messengers to the telephone and television.