When safe and practical, a lady that is in labor can and should call a car service on Shabbos to take her to the hospital. See this source from [Rabbi Moshe Heinemann](http://guidetohalachos.com/wp-content/uploads/2016/06/Guide-to-Giving-Birth-on-Shabbos-or-Yom-Tov.doc):

> Riding to the Hospital  
> A woman need not spend Shabbos/Yom Tov at a
> location close to the hospital or arrive at the hospital before labor
> starts to avoid riding on Shabbos/Yom Tov. The order of preference in
> arranging transportation for an expectant mother is as follows: 

>> A.	1st - Pre-arrange with a non-Jew. 

>> B.	2nd - Use a taxi service. (When phoning for a taxi, one should not reveal that a woman is in labor.
>> Some taxi drivers hesitate to transport a woman in labor to the
>> hospital. This is a suggestion, not a Halacha.) 

>>C.	3rd - Have a Jew
>> drive the pregnant woman. The Jew should drive normally, e.g. using
>> signals, brakes, lights, etc. The Jew should drive in the usual manner
>> because if he chooses to perform fewer Melachos, he might cause an
>> accident.

My question is would using the Uber app be preferable to calling on a regular old fashioned telephone and using a taxi service? Is using the app doing less or more Melacha?