The internet hasn’t really taken off in Cuba yet, but you can still use your smartphone to get around.
There are several offline map apps for Cuba that work fairly well.
"Galileo Offline Maps" allows you to use your phone’s GPS to show where in the world you are. You can even set Galileo to record your movements so you can see where you went! You need to download maps onto the app first before you get to Cuba and go offline.
"Cuba Travel, Cuba Guide" is an app from Cuba Travel Services, Inc. and along with city maps, has information about attractions, restaurants, cafes, and more. The app will work offline.
"Cuba Travel Guide by Triposo" is another offline app option with city maps and information about Cuba.
"Cuba Map" by City App is also available as an offline map resource, but is not always the most reliable.
I would also recommend installing a Spanish translation app that works offline.
"Google Translate" app works well to translate phrases or words from English into Spanish, and vice versa. There is a feature on this app that visually translates Spanish text into English, so you can read things that are written in Spanish with your phone. The app works offline and in airplane mode
"SpanishDict Translator" by Spanish-English Translator is another reliable, offline translation app.
If you'd like to practice your Spanish before the trip, I would recommend using the app "Duolingo."
It is a simple, free, intuitive way to learn how to speak Spanish. It sets up the different lessons as a game, to make the interaction even more stimulating. You can choose from dozens of different languages when you set up your profile. The features of Duolingo that are available offline are very limited, but it might be fun to use before you leave the United States!