Is it possible to build and release iOS applications that uses newer APIs?

Let's say I want to make an iOS application that is using new notifications on iOS 5 and fallback to old notifications on iOS 4.

Is it possible to r开发者_如何学Pythonelease such application on App Store?

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Yes, although its not pretty.

You can read about the solution I found (on Google): http://www.marco.org/2010/11/22/supporting-older-versions-of-ios-while-using-new-apis

I'm not sure if this will work with the new push notification APIs, however. I haven't had a chance to update my app yet.