What should be the size of images for background and icons for iOS

Question

Pleae consider my being very very new to iOS although I am fluent in Android, I have a requirement for one iOS project which we are outsourcing and providing graphics for, actually we are migrating this application from iOS6 to iOS7 so that it works with all the iPhone versions. Ideally what should be the size of graphics? I stumbled upon Here but found it confusing as the list seems to consider only the icons, or maybe I am not able to scour through the information. Can anyone please help me with a tabular format for images with sizes for each of the iOS versions. Or any links or even a hint?

Answer 1

I used this to determine the sizes of images for iOS specific apps.

http://www.appcoda.com/ios-univeral-app-tutorial/

Screen sizes (and thus bg image sizes) should be as follows

for non-retina iPhone (320×480)
for retina iPhone 4 and 4S (640×960)
for retina iPhone 5 (640×1136)
for non-retina iPad (1024×768)
for retina iPad (2048×1536)

Icon sizes should be as follows

for non-retina iPhone – 57×57 pixels for iOS 6 or lower, 60×60 pixels for iOS 7
for retina iPhone – 114×114 pixels for iOS 6 or lower, 120×120 pixels for iOS 7
for non-retina iPad – 72×72 pixels for iOS 6 or lower, 76×76 pixels for iOS 7
for retina iPad – 144×144 pixels for iOS 6 or lower, 156×156 pixels for iOS 7

To fulfill the requirements of universal app, other than launch images and app icons, you also need to create two different sets of application images – one version for iPhone and the other larger version for iPad. To be precise, you need to create four different versions of application images.

You should take a look at the link above to determine how exactly these images should be named and the appropriate sizes for each resolution. Naming images properly and allowing the OS to automatically select the proper one is also possible, and is discussed in detail here

How to support both iPad and iPhone retina graphics in universal apps