This pair of custom fitted bluetooth headphones tracks sleep, stress, calories burned, and focus. Seems like something the biohacking/quantified self community would be interested in supporting.
https://www.kickstar...on?ref=category
I have no affiliation with this project. Honestly, I was hoping they reached their goal so I could get one someday, so I am an unpaid shill I guess. If this is in violation of forum rules then please take down this post.