pre iPhone5
Default.png (320x480px) – "iPhone Portrait iOS5,6 – 1x"
Default@2x.png (640x960px) – "iPhone Portrait iOS5,6 – 2x" and "iPhone Portrait iOS7,8 – 2x"
iPhone5
Default-568h@2x.png (640x1136px) – "iPhone Portrait iOS5,6 – Retina 4" and "iPhone Portrait iOS7,8 – Retina 4"
iPhone 6
Default-iPhone6.png (750 x 1334) – "iPhone Portrait iOS8 – Retina HD 4.7"
iPhone 6 Plus
Default-iPhone6Plus.png (1242 x 2208) – "iPhone Portrait iOS8 – Retina HD 5.5" and "iPhone Landscape iOS8 – Retina HD 5.5"
Landscape images are not supported for earlier iPhone versions.
For iPad
Default-Portrait~ipad.png (768x1024px)
Default-Landscape~ipad.png (1024x768px)
Default-Portrait@2x~ipad.png (1536x2048px)
Default-Landscape@2x~ipad.png (2048x1536px)
Possible Other iPad Images
Default-PortraitUpsideDown.png
Default-LandscapeLeft.png
Default-LandscapeRight.png
Default-PortraitUpsideDown@2x.png
Default-LandscapeLeft@2x.png
Default-LandscapeRight@2x.png
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
Retina 4 is the same R4 asset in previous versions of Xcode to support @2x graphics on the 4 inch screen
640 x 1136 for portriat (ex. Default–568h@2x.png)
All images at 72 dpi