Looks good
This is a neat idea and seems to work well. Other heart rate variability hardware and app combinations can cost $100+, so the free price is great. Because I dont have another HRV device to compare it too Im not totally sure how accurate it is, but changing my breathing as per the instructions made me relaxed and focused.
fearlesspear about
Stress Doctor by Azumio - Stress reducer and slow breathing yoga exercise, v1.2