Particularly in stroke prevention, the detection of atrial fibrillation is of pivotal importance. Recent studies have impressively confirmed the merits of long-term monitoring. Nevertheless, and despite very mature technology, the currently available methods like long-term ECG with conductive adhesive electrodes or implantable loop recorders are burdened with disadvantages in that they are inconvenient, costly and/or invasive. A predecessor study gave us the possibility to test an app that employs photoplethysmographic signals on a smartphone camera—similar to pulse oximetry technology—to distinguish between atrial fibrillation and sinus rhythm. That retrospective study achieved a sensitivity and specificity of 95% (Krivoshei et al., Europace 2016). The prospective follow-up study DETECT AF pro is currently being conducted in cooperation with Prof. Dörr in Greifswald, Germany.