During our recent (August 2019) visit Uber in Rome was totally unreliable (trips repeatedly cancelled after driver accepted) and much more expensive than local taxi. First alternative we tried was the FreeNow app on my Android phone which worked fine, but a driver told me they don't like it because "they don't pay taxes in Italy" and prefer itTaxi app which we used extensively in Rome and Florence. Functions much like Uber, allows for storing of a credit card for payment and both on demand and scheduling in advance.