http://petersteinberger.com/blog/2014/fixing-what-apple-doesnt/

UIKitPatches.m

static void PSPDFFixCenteringInPrinterBrowserViewController(void) {
    static dispatch_once_t onceToken;
    dispatch_once(&onceToken, ^{
        // Patch the `UIPrinterSearchingView` class so we get a sane label placement in iOS 7.
        Class printerSearchingViewClass = NSClassFromString([NSString stringWithFormat:@"UI%@Searching%@", @"Printer", @"View"]);
        if (printerSearchingViewClass) {
            SEL customLayoutSubviewsSEL = NSSelectorFromString(@"pspdf_layoutSubviews");
            id customLayoutSubviews = ^(UIView *_self) {
                ((void( *)(id, SEL))objc_msgSend)(_self, customLayoutSubviewsSEL); // call original.
                @try {
                    if (PSPDFIsUIKitFlatMode()) {
                        UIView *searchingLabel = PSPDFViewInsideViewWithPrefix(_self, NSStringFromClass(UILabel.class));
                        UIView *searchingIndicator = PSPDFViewInsideViewWithPrefix(_self, NSStringFromClass(UIActivityIndicatorView.class));
                        if (searchingLabel && searchingIndicator) {
                            CGRect centeredRect = PSPDFAlignRectangles(searchingLabel.frame, _self.bounds, PSPDFRectAlignCenter);
                            CGRect searchingLabelRect = searchingLabel.frame;
                            searchingLabelRect.origin.y = centeredRect.origin.y;
                            searchingLabel.frame = searchingLabelRect;

                            CGRect indicatorFrame = searchingIndicator.frame;
                            indicatorFrame.origin.y = searchingLabel.frame.origin.y;
                            searchingIndicator.frame = indicatorFrame;
                        }
                    }
                }
                @catch (NSException *exception) {} // noncritical layout issue
            };
            PSPDFReplaceMethodWithBlock(printerSearchingViewClass, @selector(layoutSubviews), customLayoutSubviewsSEL, customLayoutSubviews);
        }
    });
}

I would use attribute(constructor)

Is [NSString stringWithFormat:@"UI%@Searching%@", @"Printer", @"View"] to prevent having UIPrinterSearchingView string in the binary and hence possible app store problems?

(awesome article by the way)