You can use both the iOS Maps SDK or a third-party service such as Google Maps SDK or even Foursquare API. I'm not sure which one lafourchette uses but here are some useful links to get you started:
iOS Maps SDK (CLGeocoder or MKReverseGeocoder) https://developer.apple.com/library/ios/documentation/userexperience/conceptual/LocationAwarenessPG/UsingGeocoders/UsingGeocoders.html#//apple_ref/doc/uid/TP40009497-CH4-SW2
Google Maps SDK
https://developers.google.com/maps/documentation/ios/start
Foursquare API