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I've only tested this on an iPhone 4 on 4.3.3 so I'm not sure if it will work on non-retina devices. Let me know if there are any issues and I'll do my best to fix them. Also, this comes with several different sliders, if you want to use a different one, navigate to Bundles/com.apple.TelephonyUI and replace the images in there with one of the other folders, e.g. "Simple Slider." Enjoy!