It gives the day to observe the crescent, the best time to observe and where to look exactly.
Age of the moon at that moment is calculated along with the crescent width and percentage of illumination.
Moreover, every hijri month start is calculated.
Similarly, it calculates Eid El Fitr and Eid Al-Ad'dha. It also gets Qibla direction and Islamic prayer times for both Shia and Sunna.