Here is an article relating to new feature enabled by iOS 11 that has doubled number of ratings for instagram in a short period of time: https://medium.com/huggingface/instagram-doubled-its-ios-reviews-in-a-week-thanks-to-this-new-in-app-review-popup-52333d4f4ce6

in essence new rating modal that allows users to rate the app without leaving it, which in my opinion is amazing feature. I'm not sure to how far it goes but if we know that users left feedback we can add rewards based on this in the app which is pretty near

I believe this is related controller? https://developer.apple.com/documentation/storekit/skstorereviewcontroller