- iPhone 3G/3GS : 320x460
- iPhone 4/4S : 640x920
- iPhone 5 : 640x1069
- iPad 1/2/mini portait : 768x1004
- iPad 1/2/mini landscape : 1024x748
- iPad retina portait : 1536x2008
- iPad retina landscape : 2048x1496
They differ from the native app splash-screen sizes because of the top-bar.
For native apps splash-screen size, please refer the Apple documentation