With the introduction of iPad, iPhone SDK 3.2 now supports development of three types
of applications: iPhone apps, iPad apps and Universal apps.
• iPhone Applications. iPhone applications are optimized to run on iPhone and iPod
touch. These applications run on iPad in their original resolution or can be optionally
set to be pixel- doubled to accommodate for the larger display.
• iPad Applications. iPhone SDK 3.2 supports the development of iPad applications
that are optimized to take advantage of iPad features, but run only on iPad.
• Universal Applications. iPhone SDK 3.2 supports the development of Universal
applications. A Universal app is optimized to run on all iPhone OS devices—itʼs
essentially an iPhone app and an iPad app built as a single binary.
This document covers the guidelines you should follow to create well-designed
A Universal app can determine which device itʼs running on and provide the best
experience for that device. Well-designed Universal apps leverage a deviceʼs unique
hardware features, provide the right choice of user interface elements, and use only the
functionality that is supported by that device.
Apple recommends that iPhone OS developers design, code and build their applications
as Universal applications. Building apps as Universal apps makes it easier for everyone.
Itʼs easier for developers because thereʼs only one app to manage on the App Store.
Itʼs easier for users because theyʼll know that it runs on any device they own