I had some free time recently, and felt like making a new watchface for my Pebble Time. The basic idea is that the outer spiral makes one revolution every hour, but the previous path of the spiral remains. Over time, the whole watchface fills up with the growing spiral.
As with my previous watchface, the code is available on GitHub. You can also download it from the Pebble App Store if you have a Pebble (it should work on the original Pebble, the Pebble Time, and the Pebble Time Round).