Here are some points UI designers must keep in mind while developing UI for iPAD apps.

1. iPad’s screen size: 1024px x 768px

2. Status bar height: 20px

3. Screen Space available for the app when running in

1. Portrait Mode: 768px x 1004px
2. Landscape Mode: 1024px x 748px

4. iPad Screen PPI: 132

5. iPad Launch Image Names and Sizes

Filename Dimensions
Default-Portrait.png 768px x 1004px
Default-Landscape.png 1024px x 748px
Default-PortraitUpsideDown.png 768px x 1004px
Default-LandscapeLeft.png 1024px x 748px
Default-LandscapeRight.png 1024px x 748px

6. iPad app icon sizes

Application icon (required for all apps) 72px x 72px
App Store icon (required for all apps) 512px x 512px
for Spotlight search results 50px x 50px
for Settings 29px x 29px
Toolbar and navigation bar icons Approximately 20px x 20px
Tab bar icons Approximately 30px x 30px

7. Photoshop PSD and Vector Templates to get started with:

iPad GUI PSD – Version 2

iPad vector GUI elements: tabs buttons menus icons

iPad GUI Kit in PSD Format

iPhone / iPad icon PSD template

8. Most important : It’s going to be used with touch (fingers not mouse pointer). Hence all UI elements must have at least 30px x 30px room so that they are comfortably touchable.

Also on touch devices, there is no “mouse over” effect.

9. Must read: iOS Human Interface Guidelines