After trying, please feedback to me so that I can improve on it. I...t uses an ordinary webcam to detect breathing and simulate heart rate variability. Download includes a user manual. Your webcam needs to be 640x480 resolution (which is what most webcams are). You can use this program to train for heart coherence similar to Wild Divine's Grapher program.
Below is a video showing comparison study between Webcam Biofeedback and Wild Divine's grapher:
