For your travels in Italy - Besides Rick Steves Audio Europe, what other (free) Smartphone apps have you found helpful ? There are so many in the Apple AppStore!
For planning - I used Kayak for air and Trivago & TripAdvisor for hotels. AirBnb also was great for BnB.
Now that almost all is planned, looking at what would be helpful once in Rome, Florence and Sorrento. Preferably that can be downloaded and used offline:
1) what is your favorite train booking app.
2) what is your favorite city guide app?
3) what is your favorite map app?
4) other ?
Thanks in advance for your time !