Simple UIButton subclass that has a nice embossed grey background drawn on to it. No bitmaps required.

AGNSimpleButton.m

//
//  AGNSimpleButton.m
//  iP2
//
//  Created by Lee Probert on 07/03/2013.
//
//

#import "AGNSimpleButton.h"

@implementation AGNSimpleButton

- (id)initWithFrame:(CGRect)frame
{
    self = [super initWithFrame:frame];
    if (self) {
        // Initialization code
    }
    return self;
}

- (void)drawRect:(CGRect)rect
{
    //// General Declarations
    CGColorSpaceRef colorSpace = CGColorSpaceCreateDeviceRGB();
    CGContextRef context = UIGraphicsGetCurrentContext();
    
    //// Color Declarations
    UIColor* baseColor = [UIColor colorWithRed: 0.218 green: 0.24 blue: 0.268 alpha: 1];
    CGFloat baseColorRGBA[4];
    [baseColor getRed: &baseColorRGBA[0] green: &baseColorRGBA[1] blue: &baseColorRGBA[2] alpha: &baseColorRGBA[3]];
    
    UIColor* upperColor = [UIColor colorWithRed: (baseColorRGBA[0] * 0.8 + 0.2) green: (baseColorRGBA[1] * 0.8 + 0.2) blue: (baseColorRGBA[2] * 0.8 + 0.2) alpha: (baseColorRGBA[3] * 0.8 + 0.2)];
    UIColor* lowerColor = [UIColor colorWithRed: (baseColorRGBA[0] * 0.9) green: (baseColorRGBA[1] * 0.9) blue: (baseColorRGBA[2] * 0.9) alpha: (baseColorRGBA[3] * 0.9 + 0.1)];
    UIColor* lightUpColor = [UIColor colorWithRed: (baseColorRGBA[0] * 0.5 + 0.5) green: (baseColorRGBA[1] * 0.5 + 0.5) blue: (baseColorRGBA[2] * 0.5 + 0.5) alpha: (baseColorRGBA[3] * 0.5 + 0.5)];
    UIColor* lightDownColor = [UIColor colorWithRed: (baseColorRGBA[0] * 0.8) green: (baseColorRGBA[1] * 0.8) blue: (baseColorRGBA[2] * 0.8) alpha: (baseColorRGBA[3] * 0.8 + 0.2)];
    
    //// Gradient Declarations
    NSArray* buttonGradientColors = [NSArray arrayWithObjects:
                                     (id)upperColor.CGColor,
                                     (id)lowerColor.CGColor, nil];
    CGFloat buttonGradientLocations[] = {0, 1};
    CGGradientRef buttonGradient = CGGradientCreateWithColors(colorSpace, (__bridge CFArrayRef)buttonGradientColors, buttonGradientLocations);
    NSArray* overlayGradientColors = [NSArray arrayWithObjects:
                                      (id)lightUpColor.CGColor,
                                      (id)[UIColor clearColor].CGColor, nil];
    CGFloat overlayGradientLocations[] = {0, 1};
    CGGradientRef overlayGradient = CGGradientCreateWithColors(colorSpace, (__bridge CFArrayRef)overlayGradientColors, overlayGradientLocations);
    NSArray* gradientColors = [NSArray arrayWithObjects:
                               (id)lightUpColor.CGColor,
                               (id)lightDownColor.CGColor, nil];
    CGFloat gradientLocations[] = {0, 1};
    CGGradientRef gradient = CGGradientCreateWithColors(colorSpace, (__bridge CFArrayRef)gradientColors, gradientLocations);
    
    //// Shadow Declarations
    UIColor* buttonShadow = [UIColor blackColor];
    CGSize buttonShadowOffset = CGSizeMake(0.1, 1.1);
    CGFloat buttonShadowBlurRadius = 2;
    
    //// Frames
    CGRect frame = rect;
    
    //// Back Rectangle Drawing
    CGRect backRectangleRect = CGRectMake(CGRectGetMinX(frame) + 1, CGRectGetMinY(frame) + 1, CGRectGetWidth(frame) - 2, CGRectGetHeight(frame) - 4);
    UIBezierPath* backRectanglePath = [UIBezierPath bezierPathWithRoundedRect: backRectangleRect cornerRadius: 4];
    CGContextSaveGState(context);
    CGContextSetShadowWithColor(context, buttonShadowOffset, buttonShadowBlurRadius, buttonShadow.CGColor);
    CGContextBeginTransparencyLayer(context, NULL);
    [backRectanglePath addClip];
    CGContextDrawLinearGradient(context, gradient,
                                CGPointMake(CGRectGetMidX(backRectangleRect), CGRectGetMinY(backRectangleRect)),
                                CGPointMake(CGRectGetMidX(backRectangleRect), CGRectGetMaxY(backRectangleRect)),
                                0);
    CGContextEndTransparencyLayer(context);
    CGContextRestoreGState(context);
    
    
    
    //// Rounded Rectangle Drawing
    CGRect roundedRectangleRect = CGRectMake(CGRectGetMinX(frame) + 2, CGRectGetMinY(frame) + 2, CGRectGetWidth(frame) - 4, CGRectGetHeight(frame) - 6);
    UIBezierPath* roundedRectanglePath = [UIBezierPath bezierPathWithRoundedRect: roundedRectangleRect cornerRadius: 3];
    CGContextSaveGState(context);
    [roundedRectanglePath addClip];
    CGContextDrawLinearGradient(context, buttonGradient,
                                CGPointMake(CGRectGetMidX(roundedRectangleRect), CGRectGetMinY(roundedRectangleRect)),
                                CGPointMake(CGRectGetMidX(roundedRectangleRect), CGRectGetMaxY(roundedRectangleRect)),
                                0);
    CGContextRestoreGState(context);
    
    
    //// Overlay Drawing
    CGRect overlayRect = CGRectMake(CGRectGetMinX(frame) + 1, CGRectGetMinY(frame) + 1, CGRectGetWidth(frame) - 2, CGRectGetHeight(frame) - 4);
    UIBezierPath* overlayPath = [UIBezierPath bezierPathWithRoundedRect: overlayRect cornerRadius: 4];
    CGContextSaveGState(context);
    [overlayPath addClip];
    CGFloat overlayResizeRatio = MIN(CGRectGetWidth(overlayRect) / 120, CGRectGetHeight(overlayRect) / 23);
    CGContextDrawRadialGradient(context, overlayGradient,
                                CGPointMake(CGRectGetMidX(overlayRect) + -53.28 * overlayResizeRatio, CGRectGetMidY(overlayRect) + -26.41 * overlayResizeRatio), 10 * overlayResizeRatio,
                                CGPointMake(CGRectGetMidX(overlayRect) + 0 * overlayResizeRatio, CGRectGetMidY(overlayRect) + -53.04 * overlayResizeRatio), 102.2 * overlayResizeRatio,
                                kCGGradientDrawsBeforeStartLocation | kCGGradientDrawsAfterEndLocation);
    CGContextRestoreGState(context);
    
    
    //// Cleanup
    CGGradientRelease(buttonGradient);
    CGGradientRelease(overlayGradient);
    CGGradientRelease(gradient);
    CGColorSpaceRelease(colorSpace);
    

}

@end