The GLKit framework provides functions and classes that reduce the effort required to create new shader-based apps or to port existing apps that rely on fixed-function vertex or fragment processing provided by earlier versions of OpenGL ES or OpenGL.

The JavaScriptCore Framework allows you to evaluate JavaScript programs from within an Objective-C or C-based program. It also lets you insert custom objects to the JavaScript environment.

MBProgressHUD is an iOS drop-in class that displays a translucent HUD with an indicator and/or labels while work is being done in a background thread. The HUD is meant as a replacement for the undocumented, private UIKit UIProgressHUD with some additional features.

The Message UI framework provides specialized view controllers for presenting standard composition interfaces for email and SMS (Short Messaging Service) text messages. Use these interfaces to add message delivery capabilities without requiring the user to leave your app.

Create previews of files to use inside your app, or perform simple edits on previews.When showing files in your app, including the ability to quickly preview a file and its content can be helpful to your users. For example, you may want to allow users to zoom into a photo, play back an audio file, and so on. Use the QuickLook framework to show a preview of common file types in your app that allow basic interactions.

StoreKit enables users to embed a store in their app. It also process financial transactions associated with the purchase of content and services.

The UIKit framework (UIKit.framework) provides the crucial infrastructure needed to construct and manage iOS apps. This framework provides the window and view architecture needed to manage an app’s user interface, the event handling infrastructure needed to respond to user input, and the app model needed to drive the main run loop and interact with the system.

Display web content in windows. Implement browser features such as following user-activated links, managing a back-forward list, and managing a history of recently visited pages. WebKit provides a set of classes to display web content in windows, and implements browser features such as following links when clicked by the user, managing a back-forward list, and managing a history of pages recently visited. WebKit greatly simplifies the complicated process of loading webpages—that is, asynchronously requesting web content from an HTTP server where the response may arrive incrementally, in random order, or partially due to network errors. WebKit also simplifies the process of displaying that content which can contain various MIME types, and compound frame elements each with their own set of scroll bars. WebCore is a framework developed by Apple, and licence under the LGPL, to provide an HTML layout engine for Mac OS X. It is one half of WebKit (the other being JavaScriptCore). WebCore combines the open source KHTML layout engine developed by the KDE project, with an adapter library called KWQ (pronounced Quack). Apple created the KWQ adapter to replace KHTML's dependency on code from the Qt toolkit and other KDE modules. KWQ also presents an Objective-C application programming interface to the C++-based KHTML rendering engine, allowing it to easily be referenced by Cocoa-based applications.

AFNetworking is a networking library for iOS and Mac OS X. It's built on top of the Foundation URL Loading System, extending the powerful high-level networking abstractions built into Cocoa. It has a modular architecture with well-designed, feature-rich APIs that are a joy to use

ASIHTTPRequest is an easy to use wrapper around the CFNetwork API that makes some of the more tedious aspects of communicating with web servers easier. It is written in Objective-C and works in both Mac OS X and iPhone applications