NDrive doesn't rise to the level of the middle-of-the-pack navigation apps because, for starters, it cannot use addresses from the Contacts book. No navigation software for the iPhone should be released without that obvious feature.
NDrive compensates somewhat by having extremely clean address recognition for manually entered locations, but mars that by showing the house address after street names for U.S. addresses in lists of recent locations.
The map shows good restraint in what street names and features are labeled, with an appearance that's easy to review at a glance, but shows too many POIs by default, cluttering the display. Advanced GPS information is available at a tap, although it's unclear why you need that within a nav app.
The app unfortunately lacks iPod control.
(This review was a part of our round-up of 12 GPS apps.)