iphone app icons - low & hi res

how can i provide both, a high and lo开发者_开发问答w resolution version of my iphone app icon ? do i "need" to provide 2 versions, or takes apple care of downsampling my high resolution icon ?

thanks

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It's optional

Check this page: http://developer.apple.com/iphone/library/qa/qa2010/qa1686.html

Note that as a standard Icon@2x.png (and all @2x prefixes) are for the retina display devices.

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You have to provide 2 icons of different resolution. How can you expect apple will take care of your application?

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You still need the low res icon for iOS versions before 4.0.