I backed this project a couple of weeks ago and it keeps getting better. They just added ANT+ (for Heart Rate broadcasting to other devices) as a stretch goal for crossing $800,000 in total funding.
LVL is a wearable hydration monitor that gives you the complete picture of your health by also tracking activity, sleep, mood and HR.
(the link is a referral one, @dreev feel free to delete if against the rules)
Also, coverage from DC Rainmaker http://www.dcrainmaker.com/2016/09/bsx-announces-kickstarter-for-new-lvl-band-wearable-hydration-sensor.html