A zmanim app according to Rabbi Ovadiah Yosef ZT"L and the Yalkut Yosef. The calculations are based off of the Ohr HaChaim calendar in Israel that Rabbi Ovadiah himself created in 1990 with Harav Shlomo Benizri and Harav Asher Darsha. He used this calendar himself until he passed. 

There is also an additional option in the settings to display the zmanim of the Luach Amudei Horaah created by Rabbi Leeor Dahan Shlita. The Amudei Horaah calendar created by Rabbi Dahan is adjusted according to the Halacha Berurah based on your location, and it should only be used outside of Israel in more northern/southern areas.

This app contains everything you could want from a jewish calendar!

Alot Hashachar/Dawn
Misheyakir
Sunrise
Latest time for Shma (MG"A and GR"A)
Latest time for Brachot Shma
Chatzot
Mincha Gedolah, Mincha Ketana, and Plag HaMincha
Sunset
Tzait Hacochavim
Rabbeinu tam!
Weekly Parasha!
Birchat HeLevana!
Birchat HaShemesh!
Mashiv Haruach/Morid Hatal
Tachanun!
Daf Yomi / Yerushalmi Yomi!

It also has features in place to help you know that your zmanim are always accurate.

Featuring a "Shabbat/Chag Mode" which allows you to see your zmanim over shabbat and chag!

This project is open source and the code can be seen at: https://github.com/Elyahu41/RabbiOvadiahYosefCalendarIOSApp

If you would like any features added, please don't hesitate to send me an email or contribute to the GitHub repository!

ACKNOWLEDGEMENTS:

I would like to thank my Rosh Yeshiva, Rabbi Yitzhak Fayazi Shlita for giving me the idea to create a zmanim app according to Rabbi Ovadiah's opinion and for the tremendous spiritual support he has given me.

I would also like to thank:

Rabbi Shlomo Benizri, Rabbi Asher Darshan, Rabbi Leeor Dahan, and Rabbi Meir Gabriel Elbaz for answering any questions I had with the halachot of zmanim.

I would also like to thank Eliyahu Hershfeld and Moshe Berman as well. Eliyahu created the KosherJava package to help the world calculate zmanim, and Moshe Berman ported it to objective-c for IOS. Thank you both, as I would never have been able to create this app without your contributions.