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This is a paid asset, but now you can download Store Product View Plugin for FREE, Please keep in mind this package is provided only for learning purposes or to be able to test before buying the product, NOT FOR COMMERCIAL PURPOSES.
Store Product View Plugin
“If possible, please buy the package to support the developer”
You don’t want your users leave your app when referring them to other apps in the iTunes App Store? This plug-in is what you need!
It displays a native App Store window within your Unity iOS-App that allows the user to purchase other media from the App Store. For example another App specified by its Appstore-ID.
This plug-in is a wrapper for the SKStoreProductViewController which is part of the iOS StoreKit.framework available in iOS 6.0 and later