In iOS, color can indicate interactivity, impart vitality, and provide visual continuity. Look to the system’s color scheme for guidance when picking app tint colors that look great individually and in combination, on both light and dark backgrounds.
While Apple calls iOS 10 their biggest release ever, most of the new features are consumer-facing, like Widgets, Siri/Messages integration, and expanded notifications.
For designers, the only noticeable design changes are bolder titles and bigger use of cards, as seen in native apps like Music and News. Whereas iOS 7 started with a widespread use of thin fonts, iOS 10 is going back to using bolder texts.