Don't limit yourself to Google. Try OpenStreetMap apps. For example OruxMaps or OsmAnd. You can easily load routes and data into those. The underlying data is free and open and you can contribute easily (and have the changes live in minutes). OsmAnd has incredibly easy ways to select POIs to highlight.
Thanks, I'll definitely look into it! Does any of those support off-line map catching? (it's hell of an important feature for me; quite recently GPS + offline maps saved my butt when I got stranded in the middle of a highway while returning from Prague via hitchhiking).