There are plenty of clock apps on the iTunes store, but they're all totally square because they divide the day into 24 hours. How arbitrary is that? Humans have ten fingers, so why shouldn't we have ten hours in a day?
In French Revolutionary Time, a day is split into 10 hours, an hour into 100 minutes, and a minute into 100 seconds. It was used officially in France from September 1794 to April 1795 as part of the French Republican Calendar.
For more information on the French Republican Calendar see its Wikipedia entry.
Questions? Comments? Contact email@example.com