A watchface that displays the local sidereal time! Sidereal time is used by astronomers to determine the positions of the stars in the sky at the current time. A sidereal day is four minutes shorter than a solar (normal) day, meaning that it's difficult to convert between the two time scales. This Pebble app takes care of all of that for you! 

It even automatically sets your time zone information and longitude to ensure the most accurate possible time estimate!