Driving solo in Tuscany

Your phone will work well. I’d recommend Waze over google maps. Google wasn’t worried about sending me into a ZTL and I had to turn around and switch apps.

Enryu,

I often travel solo and find that car rentals are best for those locations that aren't well served by public transit, or when transit schedules don't fit my Itinerary well. Using trains or bus is much easier, and no worries about parking costs.

Note that you'll need the compulsory International Driver's Permit for driving in Italy, which is used in conjunction with your home D.L. As mentioned in the previous post, you'll also need to be vigilant to avoid the ZTL (limited traffic) zones that exist in many Italian towns. Each pass through a ZTL will result in hefty fines, which you likely won't know about until after you return home.

You should be fine. I had a navigator and she used her iPhone with no problem. You might want to take along or purchase there some sort of mount for your phone. I also suggest taking a good folding map to help you plan your day's drive. We would sit after breakfast in our agriturismo and plan our morning route. Marco, our server at the agriturismo would often help us, giving tips on what road to take and what sites to visit.

In addition to getting your IDP, search the internet to get other tips for driving in Italy. It's all pretty much common sense. Learn the signage, this will go a long way to avoid mistakes. Also be aware that there are automated speed detectors. Just because you don't see a policeman doesn't mean you won't get a ticket for speeding. All of Europe, including Italy has a much lower tolerance for speeding. Hopefully you'll get a car similar to the one we got in France the last time we rented a car. It knew the speed limit and would flash a red warning if you exceeded it even by a few km/hr. Once in a while a resident would get a little impatient with our pace. It look at the first opportunity to pull over safely and let them pass. I'd usually get a wave of appreciation. Who wants to speed through the lovely Tuscan countryside anyway?

ZTLs are well marked and easily avoided. As a rule of thumb, assume anywhere within the walls of a hill town is ZTL. We spent a wonderful week driving all over Tuscany and with just a little common sense and situational awareness were able to avoid getting either a speeding ticket or ZTL infraction.

I use an iPhone 8 Plus and it works.
Learn about ZTL and Italian road signs (Wikipedia has an article).
Abide by the ZTL restrictions and speed limits. Both are enforced by thousands of hidden cameras throughout Tuscany alone, so just because you don’t see cops around it doesn’t mean they can’t see you. Use Waze for navigation, it is the best app to warn you about hidden speed cameras.