The new iPhone Software Development Kit 3.1 is now available to download by registered iPhone developers, and includes iPhone simulator, Xcode IDE and various new tools for iPhone application development reports softpedia.

As usual right on the heels of iPhone OS 3.1 Apple push out the updated SDK 3.1 so developers can gain the best updated application development tools available, so if you are an iPhone developer now is the time to grab iPhone SDK 3.1.

iPhone 3.1 update isn’t packed solid with enhancements and new features but does deliver about a dozen changes to the iPhone software.