iOS 9.3 is coming in the Spring and will introduce Night Shift as well as a number of other new features.
Apple Virtual Arc-Shaped Keyboard Patent
The recent patent application offers more refinement to the earlier touch screen interface filings (Gallery).
The virtual keyboard is described as learning over time based on which keys are pressed more often and adjusting the sensitivity of those keys. "That likelihood is determined by the person's distance of touch from the closest key, as well as frequency of use."
Another patent that has received much attention recent is Apple's Integrated Sensing Display which was previously posted and discussed in January 2006.