Capturing a Screenshot on Your iOS Device
On the device, configure the screen the way you want it.
In the Devices organizer, select Screenshots in the device.
Click New Screenshot.
Capture a screenshot on your device to document your progress during development, and create launch images for your iOS apps.
When generating your app’s default images, you should always capture images from devices with the appropriate screen size and resolution. For a universal app, this means capturing screenshots both from an iPad and from an iPhone or iPod touch. For an app that also supports Retina displays, it means capturing screenshots from an iPhone 4 in addition to any other devices.
© 2012 Apple Inc. All Rights Reserved. (Last updated: 2012-06-11)