Wearable tech is all the rage these days, but this emerging movement seems more akin to home 3D in it's ability to try and create a market that just isn't there, or perhaps just isn't ready yet for prime time based on current technology.
Who knows, maybe you want and need to know when you may die, kind of like you may want to see how much in debt the US is in on a daily basis. Hate to break it to everyone, but people live in denial for a reason.
What I think would be a lot more valuable here is a end of marriage watch. At least then you have something to look forward to once the timer runs down.