iOS 9.3 is coming in the Spring and will introduce Night Shift as well as a number of other new features.
Apple Delays Leopard Release [Updated]
iPhone contains the most sophisticated software ever shipped on a mobile device, and finishing it on time has not come without a price -- we had to borrow some key software engineering and QA resources from our Mac OS X team, and as a result we will not be able to release Leopard at our Worldwide Developers Conference in early June as planned.Apple goes on to state that while Leopard will be feature-complete by WWDC, they could not "deliver the quality release that we and our customers expect from us." As if to demonstrate that point, Apple recently released a new build of Leopard which continued to contain a long-list of known issues.
Developers will be given a "near-final" beta copy of Leopard at the Worldwide Developers Conference in early June.