Going off that. It would be pretty cool if there was an app that showed your average death-date but also connected to multiple platforms to show extensions in your death date. Hey you got your resting heart rate down X, ran Y miles last month and had cholesterol drop Z, you extended your life an estimated ~1.5 years!
It seems to operate off of a unix timestamp and doesn't mind future values, so throw the unix timestamp of your expected death-date in there and watch it count down :)
Have tried similar, and included a widget on my phone's home screen. Moved too slowly to be motivating/demotivating, though could be interesting longer-term.