UIView+Blur.h

#import <UIKit/UIKit.h>

@interface UIView (Blur)
- (void)blur;
- (void)blur:(CGSize)size;
@end

UIView+Blur.m

#import "UIView+Blur.h"

@interface FunBlurView : UIView
@property UIToolbar *toolbar;
@end

@implementation FunBlurView
- (id)initWithSuperview:(UIView*)view size:(CGSize)size {
    self = [super initWithFrame:CGRectMake(0, 0, size.width, size.height)];
    self.clipsToBounds = YES; // toolbar draws a thin shadow on top without clip
    self.toolbar = [[UIToolbar alloc] initWithFrame:[self bounds]];
    [self.layer insertSublayer:[self.toolbar layer] atIndex:0];
    return self;
}
- (void)layoutSubviews {
    [super layoutSubviews];
    [self.toolbar setFrame:[self bounds]];
}
@end

@implementation UIView (Blur)
- (void)blur {
    [self blur:self.frame.size];
}
- (void)blur:(CGSize)size {
    [self addSubview:[[FunBlurView alloc] initWithSuperview:self size:size]];
}
@end