In the letter the company sent out to users and posted by MacRumors, Apple suggests using Family Sharing instead. Sharing gives up to six family members access to each other's purchases. There's also Ask to Buy, which kids can use to send you a request whenever they want to get something from the App Store. While the feature itself will no longer be available, any allowance money left over will still be available for use. After that, well, you can use either option above or just buy your kids some iTunes gift cards.