App ratings and reviews on the App Store are viewed as essential by app developers. It is a perception that apps with more reviews are more popular, and thus can attract more downloads. Many iOS apps implement in-app pop-up to prompt user to submit rating and review.
Starting with iOS 11, Apple is forcing developers to use its API to implement in-app ratings/review pop-up. The API limits the number of times app can ask for a rating. For those who are annoyed by these pop-ups, there is now a setting that allows you to turn-off such prompts for all apps.
Go to Settings > iTunes & App Store, toggle off the switch “In-App Ratings & Review”. That’s all you need to avoid in-app ratings/reviews prompts for all apps.