vigil watches for you checking in on a schedule you set. Miss it, and a payload you wrote once — a message, a file, an instruction — gets released to whoever you named. There's no account to recover, no password reset: the management token you're given at creation is the whole of it.
Your payload is encrypted the moment you write it, in a way that can't be opened early — not by an attacker, and not by vigil's own operator either. Every check-in renews that protection, so a switch that's been running a long time doesn't quietly become weaker than a new one. If you stop checking in, release happens on schedule, whether or not vigil's server is even watching by then.
For other people — the classic case. Family passwords, account access, a final message, instructions for handling something you managed alone. If something happens to you, they don't have to guess, and you don't have to keep re-explaining it to them while you're still around.
For your future self — the case people plan for last. Devices get seized. Phones get destroyed or confiscated. People get detained, arrested, or simply lose access to the one machine that held their keys. A vigil switch you check into yourself is a way to repossess your own secrets later — a recovery path that doesn't depend on you still having whatever you started with. Name yourself, a future email you'll still control, or both.
Every other tool here is ephemeral on purpose — vigil is the opposite on purpose. Durability across weeks, months, or years is the entire point of a dead-man's switch, so vigil keeps a real durable copy (cinder's own memory-only relay can't hold something for two years) and says so plainly rather than pretending otherwise.