HRV Explorer is a smartphone enabled heart rate variability (HRV) assessment tool. It has been observed that HRV is a better predictor of cardiac abnormalities than HR itself. The reduced HRV shows changes in the cardiac autonomic control before it is manifested by HR on the disease onset. The incorporation of HRV analysis in smartphone can assist physician to analyze long/short term interbeat interval (IBI) signals extracted from ECG recording automatically for clinical decision making. It has been design to record the ECG, display it on the screen, and transmit it to the physician/server for analysis. The device provides the information about time domain HRV measures. This can be shared with the physician for diagnosis and decision making. Furthermore, patients or persons at risk of cardiac disease can benefit from HRV Explorer as it assists them early risk assessment before the onset of disease.