I still have no intention of driving in Rome. Wonder if they have an App for Florence.
Expensive: since it looks like it would require data usage to be any good. Dangerous: since it would be much like texting and driving. Stupid: since the ZTLs are well-signed. Unevaluated: since it says so. Junk: because it is.
What I'm still puzzled is why TomTom, Garmin and other GPS makers don't include that info (and also German environmental zones where you need a sticker) in their maps. It should be a no-brainer.