With next MBS FileMaker Plugin you can ask the user to review your application. The StoreKit.RequestReview function allows you to ask the user to rate your application. The function returns directly and the dialog shows asynchronously.
For the next MBS Plugin we work on functions for the Mac and iOS App Store. While this is still work in progress and getting your iOS or Mac App in the app store is quite a challenge, we prepare the necessary functions to do sell items to the user. For example you could have a solution where user buys a subscription or upgrades from trial to full