updated 05:30 pm EDT, Thu July 15, 2010
Applies to iPad, iPhone, iPod touch
In parallel with the release of iOS 3.2.1 and 4.0.1 for the public, Apple has posted iPhone SDK 4.0.1 for developers. The software is essential for creating iOS apps, as it includes the latest Xcode IDE and iPhone Simulator packages, along with other related tools. Programmers with devices upgraded to v3.2.1 or v4.0.1 must install the SDK to continue development, Apple cautions.
The SDK applies to work for the iPad and iPod touch as well as the iPhone. The iPhone is currently Apple's biggest focus though, since it is trying to cope with reception problems that may mandate a hardware solution. iOS 4.0.1 changes the way iPhones report signal quality, which was initially promised to be the answer to reception complaints.