The app receives heartbeat-to-heartbeat distances via a Bluetooth 4.0 chest strap (must be purchased separately) ECG accurately, calculates the standard heart rate variability values and displays them graphically. The displayed values quickly and understandably show the state of the autonomic nervous system in terms of current stress load and stress response. With 3 fixed and 1 flexible profile, family members or friends can be measured and the data displayed as a history monitor. Various export functions allow sending as PDF or further processing with scientific evaluation systems