To open Google Maps with directions, i'm using a formatted NSString inside a NSURL. But it doesn't work with [[UIApplication sharedApplication] openURL:nsurl];
code:
NSString * directionsURL = [NSString stringWithFormat:@"http://maps.google.com/maps?daddr=%@&saddr=%@", @"Hartenseweg 16, Renkum", @"1 Infinte Loop, Cupertino"];
[[UIApplication sharedApplication] openURL:[NSURL URLWithString:directionsURL]];