GPS app to follow a prepared itinerary
Here is what I ended up doing, it works well:


On your computer's Firefox, install the GMapToGPX bookmarklet.
Prepare your itinerary with Google Maps Itinerary.
While still on the Google Maps page, click on the GMapToGPX bookmarklet. It opens a GPX conversion dialog.
Click on the blue tab buttons to make them read like this: "Route Track Points About". It will not work otherwise.
Copy-paste the XML text in a new file, for instance myitinerary.gpx
On Android, install Maverick.
Copy your GPX file to /sdcard/maverick/tracks
In Maverick, select the track file
Scroll your way along the route at appropriate zoom levels to store the tiles in the cache.


The free version of Maverick allows 3 tracks files.