I have troubles installing quartzcore on Xcode 4 regarding an iOS application. I just can't find the answer: how to do it? Because when I try to add Quartzcore to the targets of the project, it seems I can only add a Mac OS X framework. All you can do about an iOS framework is creating one.
In Xcode 4, in the left sidebar, select the project file at the top:
1) Make sure your target is selected in the main view, and you should see 5 tabs at the top,
2) Click the "Build Phases" tab,
3) Click the arrow to the left of the "Link Binary With Libraries" row,
4) Click the plus button that just appeared at the bottom of that row,
5) Type "QuartzCore" into the search field,
6) You should see a folder named "iOS 4.3" with the "QuartzCore.framework" inside of it,
7) Double click the "QuartzCore.framework" to add it to your current project.
Then it should appear in left sidebar, and you can drag it into the frameworks folder if you wish.
Make sure you do a
#import <QuartzCore/QuartzCore.h>
in any source files that you use the framework.
If you don't see the framework when you search for it, it means you don't have the SDK installed correctly. You probably want to reinstall Xcode at that point.