gistfile1.m

- (UIImage*)tintedImageWithColor:(UIColor*)tint {
  CGSize size = self.size;
  CGRect imageBounds;
  if ([[UIScreen mainScreen] respondsToSelector:@selector(scale)] && 
      [[UIScreen mainScreen] scale] == 2) {
    imageBounds = CGRectMake(0, 0, size.width * 2, size.height * 2);
  } else {
    imageBounds = CGRectMake(0, 0, size.width, size.height);
  }
  
  UIGraphicsBeginImageContext(imageBounds.size);
  CGContextRef context = UIGraphicsGetCurrentContext();
  [self drawInRect:imageBounds blendMode:kCGBlendModeNormal alpha:1.0];  
  
  [tint set];
  CGContextSetBlendMode(context, kCGBlendModeSourceIn);
  CGContextFillRect(context, imageBounds);
  UIImage* tintedImage = UIGraphicsGetImageFromCurrentImageContext();
  UIGraphicsEndImageContext();
  return tintedImage;
}