How to download offline maps ?
1) Open the main menu via this icon : 
2) Select the "Download maps" tab. From there, all your downloaded areas are listed.
3) If you want to download a new zone, tap the icon
at the bottom right-hand corner of your screen .
4) Then select the map types you want for the download.
5) To continue the download, press "Next" and select the download area.
6) To do this, you can search for a specific place by clicking on the magnifying glass 
7) Then you can choose a download radius by pressing "Select area".
8) If you want a more precise map, you need to check the box "More accurate maps" (Note : this option is not always available. It depends on the type of maps).
9) Make sure to press the "Validate" tab and enter a name for the downloaded area.