Actually, I'd love a generalized countdown clock. Not necessarily for my lifespan, but set it up for goals like, "My side project will be profitable in 2 months."
They exist. I use one that counts down to anniversaries, birthdays, and project milestones. It's not good enough to merit mentioning, but if you search the app store for 'countdown', you'll find several.
kfk|12 years ago
esw|12 years ago