With the new publication of Dr Harun Resid Acaroglu „The Calculation of Islamic Prayer Times: Accommodation to the Four Sunni Schools“, it becomes very clear that having a method with 19° would be very useful for this app. Many people use this method. It would also make sense because some calculation methods use even 20 oder 21 degrees. I would like to adjust that and not be stuck at 19,5°.
It would be also considerable to have Tamkin withit, e.g. how Fazilet or other methods do it, the corrections made for considering the sun not as dot but as a sphere and the locations with its hights.