Change order of read items with VoiceOver

The easiest answer to this lies in creating a UIView subclass that contains your buttons, and responds differently to the accessibility calls from the system. These important calls are:

-(NSInteger)accessibilityElementCount
-(id)accessibilityElementAtIndex:
-(NSInteger)indexOfAccessibilityElement:

I've seen a few of these questions, and answered one before, but I've not seen a generic example of how to reorder the VoiceOver focus. So here is an example of how to create a UIView subclass that exposes its accessible subviews to VoiceOver by tag.

AccessibilitySubviewsOrderedByTag.h

#import <UIKit/UIKit.h>
@interface AccessibilitySubviewsOrderedByTag : UIView
@end

AccessibilitySubviewsOrderedByTag.m

#import "AccessibilityDirectional.h"
@implementation AccessibilitySubviewsOrderedByTag {
    NSMutableArray *_accessibilityElements;
}
    //Lazy loading accessor, avoids instantiating in initWithCoder, initWithFrame, or init.
-(NSMutableArray *)accessibilityElements{
    if (!_accessibilityElements){
        _accessibilityElements = [[NSMutableArray alloc] init];
    }
    return _accessibilityElements;
}
// Required accessibility methods...
-(BOOL)isAccessibilityElement{
    return NO;
}
-(NSInteger)accessibilityElementCount{
    return [self accessibilityElements].count;
}
-(id)accessibilityElementAtIndex:(NSInteger)index{
    return [[self accessibilityElements] objectAtIndex:index];
}
-(NSInteger)indexOfAccessibilityElement:(id)element{
    return [[self accessibilityElements] indexOfObject:element];
}
// Handle added and removed subviews...
-(void)didAddSubview:(UIView *)subview{
    [super didAddSubview:subview];
    if ([subview isAccessibilityElement]){
        // if the new subview is an accessibility element add it to the array and then sort the array.
        NSMutableArray *accessibilityElements = [self accessibilityElements];
        [accessibilityElements addObject:subview];
        [accessibilityElements sortUsingComparator:^NSComparisonResult(id obj1, id obj2){
            // Here we'll sort using the tag, but really any sort is possible.
            NSInteger one = [(UIView *)obj1 tag];
            NSInteger two = [(UIView *)obj2 tag];
            if (one < two) return NSOrderedAscending;
            if (one > two) return NSOrderedDescending;
            return NSOrderedSame;
        }];
    }
}
-(void)willRemoveSubview:(UIView *)subview{
    [super willRemoveSubview:subview];
    // Clean up the array. No check since removeObject: is a safe call.
    [[self accessibilityElements] removeObject:subview];
}
@end

Now simply enclose your buttons in an instance of this view, and set the tag property on your buttons to be essentially the focus order.

You can change the order setting the view's accessibilityElements array:

self.view.accessibilityElements = @[self.view1, self.view2, self.view3, self.view4];

or

self.anotherView.accessibilityElements = @[self.label1, self.txtView1, self.label2, self.txtView2];

If you need to set the interaction enabled programmatically:

[self.view1 setUserInteractionEnabled:YES];

If the view is hidden the voice over will not pass through it.