This educational application is intended for physicians, medical students, and paramedics with basic understanding of the ECG, not for lay people. The app wants to familiarise them with the specifics of the athlete’s ECG, based on the Seattle criteria (Drezner et al., Br J Sports Med 2013). The ECG is advocated during preparticipation eligibility evaluation of athletes. The Seattle criteria aim to optimise sensitivity while reducing false positive identification of athletes at risk for sudden cardiac death.