I'm working on an anonymous Dead Man's Switch (https://alcazarsec.com/deadmanswitch). You don't need any personal information to sign up, and you can configure email messages that will be automatically sent only when you stop checking in.
This can be useful for families handling digital legacy, solo founders, journalists, and others.
Let me know if you give it a try!
What would happen to the service when you've died? How long after you've died, it stop working? That's the real problem with it.
If your app, pays for its own costs, it can live long after you've gone. You may have to use dApps (Decentralized Applications) on blockchains.