Mercury’s iOS UI kitis the he most complete, most up-to-date, most accurate, and most thoughtfully structured iOS 9 UI kit available for Illustrator and Sketch. Absolutely free!
Along with an extensive collection of navigation bars, segmented controls, table views, keyboards, and other reusable system components to help you build iPhone app mockups more quickly and efficiently, this kit includes a near complete set of Apple’s system icons for navigation bars, toolbars, tab bars, activity sheets, quick actions, settings, and weather.
These icons are a handy resource to refer to ensure that your icons fit alongside the iOS system icons and are harmonious from a size, weight, and style perspective.
This kit also includes a collection of over 80 recreated full-screen Apple system app screens to review, study, and reference. This is by far the largest resource of system apps you can find.