Complex sentence: Another application called "Antikythera" emulates some of the functions of the Antikythera mechanism by calculating the phase of the moon and is accurate to within one day in 500 years.
Split into simpler sentences: Another application called "Antikythera" emulates some of the functions of the Antikythera mechanism by calculating the phase of the moon. It is accurate to within one day in 500 years.