Nav4All works great in germany, too. It's not only voice-, but also arrow-guided, and if you press the "2"-key, a map with your route is shown.
Another java-app is from
Kostenlose Handy-Navigation Ö-NAVI von DasÖrtliche, a phone-book making publishing house. Works not bad, you may search for several points of interest als destination, but there will always be advertising on the screen, so you will have more bytes to download. So keep in mind your data-plan.
Regards, Frank