The detection of atrial fibrillation (AF) is important for stroke prevention in patients with AF. This paper aimed to investigate the current landscape of smartphone-based arrhythmia detection and monitoring. The current technology can be divided into smartphone-based photoplethysmography (PPG) and smartphone-based single-lead electrocardiograms (ECGs). Our literature review concluded there are currently no validated PPG applications for the detection of arrhythmias available to the general population. However, an initial validation study indicates that the currently in development Cardiio Rhythm PPG application, when made available, could provide an accurate and reliable means to detect AF in patients at risk of developing AF. The smartphone-based single-lead ECG devices are more promising. Multiple studies have shown the AliveCor smartphone ECG to be a reliable and accurate means of detecting atrial fibrillation. A drawback is that this device strictly provides data and is not capable of making a diagnosis of atrial fibrillation. The recorded ECG needs to be sent to a physician or medical professional for further review. In conclusion, these devices show promise in arrhythmia assessment, managing patients with AF, and diagnosing AF early in high risk patients. Caution should be used when assessing data provided by these devices, as validation in a real-world setting is still underway.