I participated in the Hack.UVA Hackathon this weekend, and while there, I created a Dark Souls-themed watchface for my Pebble smart watch. The watchface displays the time, date, year, bluetooth connection status, and charging status of the watch.
During normal use, the center of the watchface shows Solaire of Astora (a character from Dark Souls) praising the Sun:
...and when the watch is charging, Solaire is shown resting at a bonfire (a key gameplay element of Dark Souls):
Below is a quick video of the transition taking place (I was quite happy to get this working). The underlaying Pebble OS is able to tell when the charging cable is plugged in and can trigger an event for the watch to switch images.
The code for this watchface is all open-source and available for download on my Github page. Enjoy!