Internet connection

The apps I used worked off line. Make sure you set them up before you leave home or when you have good wifi. The exception is for any links to live maps or to services such as booking.com.

My favourite was WisePilgrim guide and the backup was TrailSmart.

@The World My Village just to clarify the apps use the GPS built into your phone, so they can locate your position on the downloaded maps, apps, etc. You will need to review your location services settings. It may require some active management to ensure that you do not wear your battery down (enable/disable location services).

While the Internet is generally accessible along the route (both via wireless and wifi) there are spots that don't have coverage and hotels/auberges/hostels that have limited to very bad coverage (particularly at times when all the pilgrims are on the same bandwidth). I carried both capabilities (phone and paper) and found that I used the paper more just because it was quicker to pull out and check while walking. When I finally got somewhere for the night, I used the phone app to plan out the next day and take a quick look at the route. As stated above, make sure that you review all the app/system settings to minimize the battery usage. That tends to be more of a problem than you might think (particularly if you're also using the phone to take pictures or play music (as a note, I thought I was going to do the later but ended up not listening to a note of music - listening to the world around me while walking or waiting was much more fun).