CocoaPods (recommended)
Add the following line to your Podfile:
pod 'GUITabPagerViewController', '~> 0.1.0'
And then add #import <GUITabPagerViewController.h> to your view controller.

Manual
Copy the folders Classes to your project, then add #import "GUITabPagerViewController.h" to your view controller.

To use it, you should create a view controller that extends GUITabPagerViewController. Write your viewDidLoad as follows:

- (void)viewDidLoad {
  [super viewDidLoad];
  [self setDataSource:self];
}

- (void)viewWillAppear:(BOOL)animated {
  [super viewWillAppear:animated];
  [self reloadData]; }

Then, implement the GUITabPagerDataSource to populate the view. The data source has a couple of required methods, and a few more optional.

The data source methods will allow you to provide content to your tab pager view controller.

- (NSInteger)numberOfViewControllers;
- (UIViewController *)viewControllerForIndex:(NSInteger)index;

Note that despite being optional, the tab setup will require you to return either a UIView or an NSString to work.

- (UIView *)viewForTabAtIndex:(NSInteger)index;
- (NSString *)titleForTabAtIndex:(NSInteger)index;
- (CGFloat)tabHeight;  // Default value: 44.0f
- (UIColor *)tabColor; // Default value: [UIColor orangeColor]
- (UIColor *)tabBackgroundColor; // Default: [UIColor colorWithWhite:0.95f alpha:1.0f];
- (UIFont *)titleFont; // Default: [UIFont fontWithName:@"HelveticaNeue-Thin" size:20.0f];
- (UIColor *)titleColor; // Default: [UIColor blackColor];

The delegate methods report events that happened in the tab pager view controller.

- (void)tabPager:(GUITabPagerViewController *)tabPager willTransitionToTabAtIndex:(NSInteger)index;
- (void)tabPager:(GUITabPagerViewController *)tabPager didTransitionToTabAtIndex:(NSInteger)index;

There are two public methods:

- (void)reloadData;
- (NSInteger)selectedIndex;

reloadData will refresh the content of the tab pager view controller. Make sure to provide the data source before reloading the content.

selectedIndex will return the index of the current selected tab.