iOS 9.3 is coming in the Spring and will introduce Night Shift as well as a number of other new features.
Apple Removes 'Rate on Delete' for Apps in iPhone 4
Rate on delete feature introduced in iPhone OS 2.2
Developers will be pleased to learn that Apple has removed a controversial "Rate on Delete" feature from iPhone 4. Starting in iPhone 2.2, when a user deleted an App from their iPhone, the operating system would ask the user to rate a App using the 1-5 star rating system in the App Store. The move was presumably meant to increase rating participation in the App Store.
However, many developers were unhappy with the system as they felt it skewed the ratings downwards. The system increased the number of ratings from customers who were likely unhappy with an app, while those who kept an app on their iPhone would never be prompted for a rating.