saving maps to view off line. I just cant get this to work

Myself and friends just cant work this out. I am off cycling in the mountains of Northern Spain on Monday. There will be times when there is no internet reception.. We need to download routes and to be able to read them off line. 

I have tried downloading one of the squares containing the routes then going in to airplane mode, but it just doesnt work for me. This is what I have done.

Open app. Display route I want to ride. Go to settings/offline map. Click on the area I want to download. It turns from purple to green. Tap download. Test by closing app and switching to airplane mode.  Open app. Open routes. This opens a page titled. Downloaded routes. It is blank.

Can anyone help. It doesn't seem as straightforward as I had hoped... Thanks, Tony.

Impressed

Tried the android app on a ride for the first time. Impressive. Did everything it needed to. Cant really fault it or think if any improvements right now other than one day having os and ign backgrounds available as they are in a PC. 

Km to miles

HHow do i change from km to miles. Thanks