The map of Messina is based on OpenStreetMap; you can verify the level of detail on the left-hand map.

In addition to street names, transport stops and other amenities, you can view, search and bookmark the following map features (restaurants, shops, bars...):

The offline map of Messina also includes these areas:
Milazzo, Lipari, Barcellona Pozzo di Gotto, Bronte, Patti, Reggio di Calabria, Capo d'Orlando, Messina, Randazzo, Villa San Giovanni, Linguaglossa, Taormina, Sant'Agata di Militello, Troina.

When you download this map, you also get full Wikipedia articles and photos for the area, available to search and view, even without an internet connection.