I'm currently doing an in app purchase iphone app. This is what i do: User use the app. Click on the item which he want to purchase (in app).App store or apple will charge the user.Then the item will download from our server (not app store) and store in user iphone. Im using storekit framework to do this. It can be successful done if the item is mp3 file. The user can paid and download the mp3 from our server and play it. But it cannot done with ipa file. How to let the user download the ipa file and install from our server?