[This corrects the article DOI: 10.2196/12637.].
©Sandra Barteit, Florian Neuhann, Till Bärnighausen, Annel Bowa, Sigrid Lüders, Gregory Malunga, Geoffrey Chileshe, Clemence Marimo, Albrecht Jahn. Originally published in JMIR Mhealth and Uhealth (http://mhealth.jmir.org), 03.04.2019.