About prayer times in New York
ISNA (Islamic Society of North America) is the most widely-followed calculation method across the United States, and is what Sajjada defaults to for New York. Local mosques may vary slightly on Fajr and Isha angles, you can change the method in settings.
The five daily prayers
The five salah are the spine of a Muslim's day: Fajr before dawn, Dhuhr after the sun passes its zenith, Asr in the afternoon, Maghrib just after sunset, and Isha at night. Each is a window, you have until the next prayer begins to offer it, though earlier is always better.
Calculation method matters
Different parts of the Muslim world use different methods to determine Fajr and Isha, the times where the sun is below the horizon and angles vary. Local mosques in United States typically follow the ISNA method, which is what Sajjada uses by default for New York. You can switch to any of the other major methods (ISNA, Muslim World League, Umm al-Qura, and others) in the app's settings.
The qibla from New York
From New York, the qibla, the direction of the Kaaba in Mecca, can be found instantly with the Sajjada compass. The app uses your phone's magnetometer and calibrates against your current GPS position for accuracy.