It uses the smartphone camera to read pulse, and calculate stress metrics (called Photoplethysmography). This is definitely a "rough draft", and my first android app, but I would love any and all constructive feedback. Also, because I originally built this as a personal utility, I will likely continue development for a long time coming. So anybody who finds it useful and helps me generalize its utility by providing feedback overtime will be my new best friend :)Thanks!
P.S.
Part of my goal is to the the peak detection, and eventually motion artifact reduction algorithms very transparent. This is to say I want it to be very obvious how raw data turned into the higher level biomarkers. If you have ideas on how to achieve this, I'm all ears.
https://play.google.com/apps/testing/com.martianwearables.hrv_flowt