For iOS7 create launch images in the following sizes:
For iPhone 5 and iPod touch (5th generation):
For other iPhone and iPod touch devices:
- 640 x 960 pixels
- 320 x 480 pixels (standard resolution)
For iPad portrait:
- 1536 x 2048 pixels
- 768 x 1024 pixels (standard resolution)
For iPad landscape:
- 2048 x 1536 pixels
- 1024 x 768 pixels (standard resolution)
See iOS 7 Design Resources > iOS Human Interface Guidelines > Launch Images
UPDATE 1
For iPhone 6:
- 750 x 1334 (@2x) for portrait
- 1334 x 750 (@2x) for landscape
For iPhone 6 Plus:
- 1242 x 2208 (@3x) for portrait
- 2208 x 1242 (@3x) for landscape
UPDATE 2
For iPhone X:
- 1125 x 2436 (@3x) for portrait
- 2436 x 1125 (@3x) for landscape