The development of mobile technologies has led to a growing popularity of health-related applications (m-health/ mobile health). Some of these devices enable users to register single-lead electrocardiograms, which can facilitate diagnosis and help prevent complications associated with the most common arrhythmias, such as atrial fibrillation. This study reviews the performance of devices based on oscillometry and plethysmography, as well as those capable of generating ECG recordings that may serve as a basis for atrial fibrillation diagnosis. Given the increasing prevalence of modern technologies across diverse population groups (including healthy individuals, physically active people, and patients with diagnosed cardiovascular disease), it is essential to consider the limitations associated with their use.