Zoroastrian Calendar is a free Android app developed by NETTRO Technologies LLC that aims to mix the ancient Iranian calendar with the current calendar. It is a calendar for all Iranians who want to stay connected with their roots while also keeping up with modern times.

The app allows users to see the name of ancient days and events of ancient Iran. It also provides information about the pilgrimage days of the sanctuaries and the avoidable days of eating helpful animal meat (Nabor). Users can record events and reminders on a specified day and the app has automatic updates to keep everything accurate.

Overall, Zoroastrian Calendar is a great tool for anyone interested in the ancient Iranian calendar. The app is easy to use and provides a great mix of old and new. However, it would be great to see more features added to it in the future.