Last month I made a new DS program. It's called RouteBoards.
It will show you exit/intersection boards that are on a route you made yourself!
Usage:
1. Make your own boards and routes on your PC (Windows only).
First you have to make boards with RouteBoardsDB and put them in correct order (with a direction) with RouteBoards Editor.
RouteBoards Editor will generate the routes and a file calles Routes.sav (output dir is db/).
2. Upload the boards and routes to your flashcard.
Second you have to upload the boards and routes in a specific directory on your flashcard.
Routes (.rbr) and Routes.sav: FAT:/RouteBoards/route/
Boards (.dbe): FAT:/RouteBoards/db/
3. Open the routes on your DS.
Start RouteBoards on your DS and select a route. Now you can scroll through the boards!
In RouteBoards you can also set the brightness and the background (one for day and one for night).
In the package (.zip) are two example routes.