A custom UITabBar with a big unique center button that animates 3 buttons out of the center from any view.

ExplodingTabBar.m

#import "CustomTabBarViewController.h"

@interface CustomTabBarViewController ()
@property (nonatomic, assign) BOOL buttonsExpanded;
@end

@implementation CustomTabBarViewController

-(void) addCenterButtonWithImage:(UIImage*)buttonImage highlightImage:(UIImage*)highlightImage
{
    UIButton* button = [UIButton buttonWithType:UIButtonTypeCustom];
    button.autoresizingMask = UIViewAutoresizingFlexibleRightMargin | UIViewAutoresizingFlexibleLeftMargin | UIViewAutoresizingFlexibleBottomMargin | UIViewAutoresizingFlexibleTopMargin;
    button.frame = CGRectMake(0.0, 0.0, buttonImage.size.width, buttonImage.size.height);
    [button setBackgroundImage:buttonImage forState:UIControlStateNormal];
    [button setBackgroundImage:highlightImage forState:UIControlStateHighlighted];
    
    CGFloat heightDifference = buttonImage.size.height - self.tabBar.frame.size.height;
    if (heightDifference < 0)
        button.center = self.tabBar.center;
    else
    {
        CGPoint center = self.tabBar.center;
        center.y = center.y - heightDifference/2.0;
        button.center = center;
    }
    
    [self.view addSubview:button];
    [button addTarget:self action:@selector(centerTouched) forControlEvents:UIControlEventTouchUpInside];
    [self.view bringSubviewToFront:button];
}

- (void)viewWillAppear:(BOOL)animated
{
    UIButton *button1 = [UIButton buttonWithType:UIButtonTypeCustom];
    UIButton *button2 = [UIButton buttonWithType:UIButtonTypeCustom];
    UIButton *button3 = [UIButton buttonWithType:UIButtonTypeCustom];
    
    button1.backgroundColor = [UIColor redColor];
    button2.backgroundColor = [UIColor blueColor];
    button3.backgroundColor = [UIColor yellowColor];
    
    button1.frame = CGRectMake(self.tabBar.center.x, self.tabBar.center.y, 0.0, 0.0);
    button2.frame = CGRectMake(self.tabBar.center.x, self.tabBar.center.y, 0.0, 0.0);
    button3.frame = CGRectMake(self.tabBar.center.x, self.tabBar.center.y, 0.0, 0.0);
    
    [button1 addTarget:self action:@selector(centerTouched) forControlEvents:UIControlEventTouchUpInside];
    [button2 addTarget:self action:@selector(centerTouched) forControlEvents:UIControlEventTouchUpInside];
    [button3 addTarget:self action:@selector(centerTouched) forControlEvents:UIControlEventTouchUpInside];
    
    button1.tag = 101;
    button2.tag = 102;
    button3.tag = 103;
    
    [self.view addSubview:button1];
    [self.view addSubview:button2];
    [self.view addSubview:button3];
    
    [self.view bringSubviewToFront:self.tabBar];
    [self addCenterButtonWithImage:[UIImage imageNamed:@"cameraTabBarItem.png"] highlightImage:nil];
}

- (void)centerTouched
{
    NSLog(@"Center Touched");
    if (!self.buttonsExpanded) {
        float screenWidth = self.view.frame.size.width;
        float screenHeight = self.view.frame.size.height;
        [UIView animateWithDuration:0.20 delay:0 options:UIViewAnimationOptionCurveLinear animations:^{
            [[self.view viewWithTag:101] setFrame:CGRectMake((screenWidth/3 - 66.0), (screenHeight - 130), 66.0, 66.0)];
        } completion:^(BOOL finished) {
            [UIView animateWithDuration:0.10 animations:^{
                [[self.view viewWithTag:101] setFrame:CGRectMake((screenWidth/3 - 22.0), (screenHeight - 100), 44.0, 44.0)];
            }];
        }];
        [UIView animateWithDuration:0.20 delay:0.05 options:UIViewAnimationOptionCurveLinear animations:^{
            [[self.view viewWithTag:102] setFrame:CGRectMake((screenWidth/2 - 33.0), (screenHeight - 180), 66.0, 66.0)];
        } completion:^(BOOL finished) {
            [UIView animateWithDuration:0.10 animations:^{
                [[self.view viewWithTag:102] setFrame:CGRectMake((screenWidth/2 - 22.0), (screenHeight - 150), 44.0, 44.0)];
            }];
        }];
        [UIView animateWithDuration:0.20 delay:0.10 options:UIViewAnimationOptionCurveLinear animations:^{
            [[self.view viewWithTag:103] setFrame:CGRectMake((2*screenWidth/3 - 0.0), (screenHeight - 130), 66.0, 66.0)];
        } completion:^(BOOL finished) {
            [UIView animateWithDuration:0.10 animations:^{
                [[self.view viewWithTag:103] setFrame:CGRectMake((2*screenWidth/3 - 22.0), (screenHeight - 100), 44.0, 44.0)];
            }];
        }];
        
        self.buttonsExpanded = YES;
        
    } else {
        [UIView animateWithDuration:0.25 animations:^{
            [[self.view viewWithTag:101] setFrame:CGRectMake(self.tabBar.center.x, self.tabBar.center.y, 0.0, 0.0)];
            [[self.view viewWithTag:102] setFrame:CGRectMake(self.tabBar.center.x, self.tabBar.center.y, 0.0, 0.0)];
            [[self.view viewWithTag:103] setFrame:CGRectMake(self.tabBar.center.x, self.tabBar.center.y, 0.0, 0.0)];
        } completion:^(BOOL finished) {
            self.buttonsExpanded = NO;
        }];
    }
}

Note:
The buttons being created in viewDidLoad could be created in the storyboard and connected with an IBOutlet.