iOS Resolution

Useful info about iOS devices:

iPhone Resolution
iPhone 3GS 480-by-320-pixel resolution at 163 ppi
iPhone 4S 960-by-640-pixel resolution at 326 ppi
iPhone 5 1136-by-640-pixel resolution at 326 ppi
iPad 4 2048-by-1536 resolution at 264 ppi
iPad mini 1024-by-768 resolution at 163 ppi
iPad 2 1024-by-768 resolution at 132 pip