Self-Assessment of Having COVID-19 With the Corona Check Mhealth App - Beierle, F.; Allgaier, J.; Stupp, C.; Keil, T.; Schlee, Winfried; Schobel, J.; Vogel, C.; Haug, F.; Haug, J.; Holfelder, M.; Langguth, B.; Langguth, J.; et al. (My University, 2023)