Lifeclocc is a Teensy-based electronic clock for your desk that counts down the seconds you (probably) have left to live.
If you live to the age of 80 you live for 2.52 billion seconds, or 29,000 days. This Teensy-based clock reminds you of your looming mortality by displaying two counters: the full days you have to live and the seconds remaining in the current day. If this is something you need in your life, you’re in luck! Chai Jia Xun is currently selling the Lifeclocc on Kickstarter.
Chai Jia Xun has published a detailed build log with schematics and progress pictures over on his blog. You can also read a write up of the project and Kickstarter campaign on the Hackaday blog.