The best free or cheap GPS navigation apps for the iPhone
Scout by Telenav is with hands down one of the best interfaces for an iPhone GPS app. Very easy to use, with a bucket load of features, including crowdsourced POIs reviewes, the only caveat is that it uses TomTom maps, which are not that great for some regions in the US, providing spotty coverage.
In fact, a recent comparison between Nokia's acclaimed Maps and NavFree on an iPhone yielded very similar results, with the open source solution getting ahead at times even, although that was in Europe, while the US navigation lacks at places.
NavFree's disadvantage is that it has a limited number of supported countries for now, though they are some of the most traveled places in the world. The caveat - the app now shows ads, but something's gotta give for you to have free offline voice-guided navigation.
The download is 1.5 GB, since it includes the maps of BOTH US& Canada for free offline use, so no data or roaming charges would be incurred while using the app. You can also purchase voice-guidance for 20 bucks one-time fee, making iGO Primo in line with the cheapest full-featured nav apps for the iPhone. 3D maps and building are also available as an in-app purchase.
The standout feature is now social integration with Facebook and Twitter, but also Google and Bing, as well as Wikipedia places info. Right now the fee to make MotionX GPS Drive a voice-guiding unit is 60% off, so for 11 bucks in total you get one of the greatest GPS apps for the iPhone, integrated with your music player and calling app, so it keeps doing its job while you listen to tunes or receive a call.
The catch - it doesn't allow offline mapping, so it will use some of your data plan, but that's what Apple or Google maps would do as well. Also, it hasn't been updated for the larger iPhone 5 screen yet, so it will appear boxed in.
6. CoPilot GPS
The free version offers most bells and whistles we are accustomed to from full-fledged GPS apps, including advanced lane guidance, but doesn't offer voice prompts, which can be an issue while driving. A $20 upgrade fee will get you those voice directions, plus speed warnings and automatic route recalculation, though.
The caveat is that maps can't be downloaded, and it relies on crowdsourced information to fight live traffic, warn about speed traps, report gas prices and so on. Not always accurate, but it's hard to beat free, and Waze is getting better by the day.