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 BSX Announces Kickstarter for New LVL Band Wearable Hydration Sensor | DC Rainmaker