Conditions for the validity of Salaah

When does the time of fajr set in?

Q: What is the degree for Fajr and isha salat according to shafii school because there a several application like adhan pro and islamic finder and I am in trouble because i don't know which is more correct according to Shafii madhaab? 19.5°(fajr)-17.5°(isha):EGAS, 15°-15°:ISNA, 18°-17°:MWL, 18.5°-90mn:UQU, 12°-12°:UOIF, 20°-18°:MUIS