In March and April 2023, the large-scale study on the DIDUNAS app in Germany was conducted. Data were collected from more than 100 Grade 1 students from three different schools. The three schools were: Gemeinschaftsgrundschule Weimarer Straße, Katholische Grundschule Zugweg, and Heliosschule. The students worked on the DIDUNAS app. Teacher feedback on the DIDUNAS app was collected to refine the app.