[This corrects the article DOI: 10.2196/11420.].
©Nadine Muller, Peter Martin Ferdinand Emmrich, Elsa Niritiana Rajemison, Jan-Walter De Neve, Till Bärnighausen, Samuel Knauss, Julius Valentin Emmrich. Originally published in JMIR Mhealth and Uhealth (http://mhealth.jmir.org), 14.10.2019.