The Contacts framework provides Swift and Objective-C API to access the user’s contact information. Because most apps read contact information without making any changes, this framework is optimized for thread-safe, read-only usage.

Core Audio is the digital audio infrastructure of iOS and OS X. It includes a set of software frameworks designed to handle the audio needs in your applications. Read this chapter to learn what you can do with Core Audio.

The Core Motion framework lets your application receive motion data from device hardware and process that data. The framework supports accessing both raw and processed accelerometer data using block-based interfaces. For devices with a built-in gyroscope, you can retrieve the raw gyro data as well as processed data reflecting the attitude and rotation rates of the device. You can use both the accelerometer and gyro-based data for games or other apps that use motion as input or as a way to enhance the overall user experience.

MediaToolbox framework contains interfaces for playing audio content.

This collection of documents describes the programming interfaces of the System Configuration framework. The System Configuration framework provides functions that determine the reachability of target hosts in both a synchronous and an asynchronous manner. It also provides error detection facilities.

The Accounts framework provides access to user accounts stored in the Accounts database. An account stores the login credentials of a particular service, such as Twitter, that can be used as authentication for the service. By implementing the Accounts framework into your app, you do not need to be responsible for storing account logins yourself. Instead, the user can grant access for your app to use their account login credentials, bypassing the need to type their username and password. If no account for a particular service exists in the user’s Accounts database, you can let them create and save an account from within your app.

The Address Book framework provides access to a centralized contacts database, called the Address Book database, that stores a user’s contacts. Applications such as Mail and Messages use this database to present information about known and unknown persons.

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.

The AV Foundation framework provides an Objective-C interface for managing and playing audio-visual media in iOS and OS X applications.

The Core Bluetooth framework provides the classes needed for your iOS and Mac apps to communicate with devices that are equipped with Bluetooth low energy wireless technology.