gistfile1.m

+ (UIImage*)imageNamedForDevice:(NSString*)name {
  
  if (UI_USER_INTERFACE_IDIOM() == UIUserInterfaceIdiomPhone)
  {
    if (([UIScreen mainScreen].bounds.size.height * [UIScreen mainScreen].scale) >= 1136.0f)
    {
      //Check if is there a path extension or not
      if (name.pathExtension.length) {
        name = [name stringByReplacingOccurrencesOfString: [NSString stringWithFormat:@".%@", name.pathExtension]
                                               withString: [NSString stringWithFormat:@"-568h@2x.%@", name.pathExtension ] ];

      } else {
        name = [name stringByAppendingString:@"-568h@2x"];
      }
      
      //load the image e.g from disk or cache
      UIImage *image = [UIImage imageNamed: name ]; 
      if (image) {
        //strange Bug in iOS, the image name have a "@2x" but the scale isn't 2.0f
        return [UIImage imageWithCGImage: image.CGImage scale:2.0f orientation:image.imageOrientation];
      }
      
    }
  }
  
  return [UIImage imageNamed: name ];

}