The goal of this app is to calculate what time is Sof Zman Rabbeinu Tam (Nightfall according to Rabbi Yaakov Ben Meir).
In order to create this app, I needed an API that would give me the sunrise and sunset times for everyday. I was recommended the KosherCocoa API, and that is the basis for this app's zmanim (time) calculations. I also added the NOAACalculator class in order to get the sunrise and sunset times according to the US National Oceanic and Atmospheric Administration Algorithm.
Included in the app, is the ability to add elevation data to the sunrise and sunset times, and in order to find out the relevant elevation data, I found a website called geonames.com that gathered this information for each city. In the app, you can choose to download your city's elevation data.
Click this link to download the app from the App Store!:
