Yahoo offers an SDK in Objective C language to integrate social features in iPhone devices. Because some users prefer a portable device, this kit can help to create applications to connect using directories and lists of contacts. Requirements include Xcode development tools, OS X 10.5 (Leopard) or higher, and iPhone Sample Code. iPhone OS 2.0+ is optional. To develop, users can obtain a new client-based application ID and OAuth consumer key and secret. They can also access the sample code available on GitHub. The social directory part of the SDK contains 2 APIs and enables applications to include user profiles, interests, contact info, age, gender, location, and photo. Accessing the contacts API, projects can encompass features of social relationships between Yahoo Mail, Yahoo Messenger, Yahoo Mobile, and third party applications.