In iOS apps, often we need to implement Index Scrolling in a TableView, just like the contacts view of an iPhone. Index Scrolling enables fast scrolling to required section without trolling through each and every sections. Since it is required in various apps , it has to be made generic, so that it can be used anywhere required. Just by adding the statements in your model class will work the whole thing out.
A basic idea of UITableView and its delegate functions.
A blog of the above project is also available at http://innofied.com/indexed-list-in-ios/ for better understanding.