Just a bit of info to share:
iPad 1, iPad 2
4:3, 1024×768
iPad 3
4:3, 2048×1536
iPhone 3GS and lower
3:2, 480×320
iPhone 4, iPhone 4S
3:2, 960×640
iPhone 5
16:9, 1136×640
WindowsPhone7
16:10, 800×480
Android tablets
16:10, 1280×800 OR 17:10, 1024×600
Android devices
4:3, 320×240; 3:2, 480×320; 16:9, 854×480 OR 16:10 800×480
