I know I'm super late to the party, but I couldn't find an accurate app icon template for Illustrator using Guides, so I made one myself. Use the Guides to snap your objects perfectly to the iOS 7 grid. Enjoy!
This is for use in conjunction with www.appicontemplate.com to export all the icon sizes once the icon is ready. The template is built at 1024x1024 but since its all vector, you can scale it to whatever size you'd like.
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