I was a longer trip with car, I used your app, and there is some practical advice (in preference order):

- Full offline mode (I preload the map tiles, but the app every half hour pop a connect window).
- Zoom (not map zoom), to see the letters. Maybe double pixel mode? N900 have good screen resolution, but in a moving car you can't read the label of cities or streets.
- Set contrast. In some map there isn't enough contrast, so you can't see the streets in a sunny summer day.
- Upside down portrait mode. (As I wrote before: because N900 charger's placement)
- If you set a marker as a target, you need an arrow, which is show the target's position if it isn't in screen.
- Permanent markers (or POIs). (To find those quick.)

I know these are many works, so I am patient, and if you share the source, I try to help you. May I get the current sources? I want to help you with implement some simple features, but the sources in the garage are 6 months old. (Or I can't found those...)

I like your app, it was very helpful the last some days, I will send you some donation today.