This is a passion project that I created while in college. The goal was to create an android app that would be able 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 KosherJava API, and that is the basis for this app's zmanim (time) calculations.
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 chaitables.com that gathered this information for each city. In the app, you can choose to navigate to the website and find your city's elevation data.
Click this link to download the app from the Play Store!:
