A pebble watchface that displays the time and date in binary format.
Because I wanted to, that's why.
UPDATE: I just wanted to say that I loved my Pebble, not only for it's simple, yet robust design, or it's equally simple yet robust interface, it was one of the easiest platforms that I have ever been able to program in. I was able to make this incredible (though grossly inconvenient) watchface within a day or two of reading on the API. They even had their own web IDE which wirelessly programmed my watchface to my Pebble through my phone, not to mention the intuitive web interface that I could program in javascript. This was a company that cared about developers. I'm gonna miss Pebble...
In Memorium: Pebble 2012-2016
Apple watch is still good though...