Night mode is an automatic setting which takes advantage of the new wide-angle camera that's in the iPhone 11 and 11 Pro models. It's equipped with a larger sensor that is able to let in more light, allowing for brighter photos when the light is low.
Apple Letting Developers Submit iOS 9, OS X El Capitan and WatchOS 2 Apps for Review
Developers are also able to seed apps with iOS 9 and watchOS 2 features to external beta testers using TestFlight. Prior to today, only internal testing was available, giving developers little time to beta test their apps.
You can now submit your apps that take advantage of the latest features in iOS, OS X, and watchOS. Build your apps using Xcode 7 GM seed, test with the GM seeds of iOS 9, OS X El Capitan, and watchOS 2, and submit them for review.Apple normally allows developers to begin submitting apps directly after golden master versions of new software are released, but this year, the iOS 9, watchOS 2 and OS X El Capitan GMs were released on Wednesday, but submissions were not allowed until this afternoon.
Following reviews by Apple's App Store review team, iOS 9 and watchOS 2 apps will begin appearing in the iOS App Store in time for the iOS 9 launch.
iOS 9 and watchOS 2 will be released on Wednesday, September 16. OS X El Capitan will be released two weeks later on Wednesday, September 30.