I find Navmii to be very good, its free if you don't mind an advert at the bottom of the screen when you are searching for your destination. For a total spend of about £4 you have no adds, traffic and speed camera alerts, also doesn't use mobile data to generate maps & street names (they're included in the initial download). It also runs your search through its own directory of streets, POI's etc and Google to give you results. It also searched FourSquare, whatever that is

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I've used this app in the UK and also the US version when I'm over there. With 3 mobile's "Feel at Home" free US Roaming it kicks the ar$e out of $10/day to hire a satnav or £50 to add the maps to my TomTom unit. Its available for iPhone (the version i use), android and probably others as well.