iOS Default langauage for localized string

NSLog(@"Welcome Text: %@", NSLocalizedString(@"WelcomeKey", @""));

@implementation Language

static NSBundle *bundle = nil;

+(void)initialize {
 NSUserDefaults* defs = [NSUserDefaults standardUserDefaults];
 NSArray* languages = [defs objectForKey:@"AppleLanguages"];
 NSString *current = [[languages objectAtIndex:0] retain];
 [self setLanguage:current];

}

/*
  example calls:
  [Language setLanguage:@"it"];
  [Language setLanguage:@"de"];
*/
+(void)setLanguage:(NSString *)l {
 NSLog(@"preferredLang: %@", l);
 NSString *path = [[ NSBundle mainBundle ] pathForResource:l ofType:@"lproj" ];
 bundle = [[NSBundle bundleWithPath:path] retain];
}

+(NSString *)get:(NSString *)key alter:(NSString *)alternate {
 return [bundle localizedStringForKey:key value:alternate table:nil];
}

@end

[[NSUserDefaults standardUserDefaults] registerDefaults:[NSDictionary dictionaryWithObject:[NSArray arrayWithObjects:@"de", nil] forKey:@"AppleLanguages"]];