Detect iPhone 4 inch

#define isPhone568 ([[UIDevice currentDevice] userInterfaceIdiom] == UIUserInterfaceIdiomPhone && [UIScreen mainScreen].bounds.size.height == 568)
#define iPhone568ImageNamed(image) (isPhone568 ? [NSString stringWithFormat:@"%@-568h.%@", [image stringByDeletingPathExtension], [image pathExtension]] : image)
#define iPhone568Image(image) ([UIImage imageNamed:iPhone568ImageNamed(image)])

UIImage *image = [UIImage imageNamed:iPhone568ImageNamed(@"Default.png")];