If you're building for iOS 26, this covers the Liquid Glass material system and the new SwiftUI APIs like WebView and Chart3D. The reference guide structure is smart: it breaks down automatic adoption (what you get for free by recompiling with Xcode 26) versus what needs explicit code. The common mistakes section is honest about real gotchas like overusing glass effects on content areas instead of navigation, and the reminder that Clear variant only works for media-rich backgrounds. Good backward compatibility guidance with availability guards for iOS 17/18 support.
npx skills add https://github.com/johnrogers/claude-swift-engineering --skill ios-26-platform