Interesting idea. My main worry about services like this is that they won't be maintained in perpetuity. Take ifidie.org -- looked to be well-maintained and organized, and now seems to be gone. I'm relying on someone I don't know to both protect my private info and to stay around for a long time (hopefully).
@zefareu hm . . . ifidie.org seems to be online to me. You make a fair point, but this is also somewhat different in that a) it's a paid service, b) it's extremely low-cost to run on AWS, c) it checks on you regularly (i.e., you'd likely notice if it stopped checking.), and d) you don't necessarily need to trust the service with private info. The message you leave can be as simple as "Please make sure I'm okay".
Thanks for submitting, Antonio!
I built this because I recently got a puppy and realized he'd be in trouble if I suddenly disappeared (e.g., if I got hit by a bus on a Friday).
This service checks in on you and lets your contacts know if you don't respond -- so they can check on your pets, hide your sex toys, etc.
More details about how I built it here: https://medium.com/@marclar/iz-u...
Thanks for checking it out!