Basicamente la diferencia con la V1.3 es que actualizaron el programa para que funcione con el iOS4 y todas sus funciones, aca les dejo el changelog en ingles:

• IF YOU HAVE ALREADY UPGRADED TO APPLE IOS 4, YOU MUST INSTALL THE LATEST TOMTOM UPDATE, VERSION 1.4, TO CONTINUE USING THE APP.
  
• SEAMLESS NAVIGATION WHILE CALLING (iPhone 3GS only): See continuous visual instructions, even when you are on a call, so you still find your way. Now making and answering calls safely won't slow you down.
  
• NEW, UPDATED MAPS: Because on average 15% of roads change every year, your TomTom app comes with the latest and most up-to-date map, ready to navigate. No mobile signal or data plan is required to browse your map and navigate to your destination.
  
• BACKGROUND NAVIGATION INSTRUCTIONS (iPhone 3GS & iPod touch 3rd Gen. only): Lets you see other apps on your screen while still receiving spoken turn-by-turn instructions.
  
• ROUTE SHARING: Share your route details with your contacts via email. Keep friends and family up to date with your plans.
  
• DEPARTURE REMINDER: Added to your calendar, departure reminders make you aware of when you need to get on the road.
  
• ECO ROUTES: Save money and reduce your impact on the environment by driving with these more fuel-efficient Eco Routes.
  
• CAR SYMBOLS: Personalize the car symbol on your driving screen. Choose from a range of car icons and symbols.

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