[jones1618]

It's memorable and could be a plausibly "cute" name for an actual hang man game. Still, it might set off alarms of the abuser who's already constantly on the lookout for emotional/physical defection by their victim.

I agree, too, the target audience might not know what a dead man switch is nor do you want them to think this is a last resort and literally only useful when they are dead. I'd market it as a "fail-safe switch" or "silent alarm." Maybe change the name to "Dead Spell Man" which sounds like something a non-English developer might call hang man and diffuses the "I want to kill my husband" kind of connotation.

Otherwise, the idea and intention of this app make it a really, really worthy thing to put out in the world.