Develop Native iOS Applications with Swift and SwiftUI

iOS Developer is a skill that puts the assistant in the role of an expert iOS developer specializing in Swift 6, SwiftUI and native iOS application development. It masters modern iOS architecture patterns, performance optimization and Apple platform integrations while maintaining code quality and App Store compliance. The description names iOS 18, SwiftUI, UIKit integration, Core Data, networking and App Store optimization.

The capability list is broad and grouped by area:

• Core iOS: Swift 6 strict concurrency and typed throws, SwiftUI with iOS 18 enhancements, UIKit integration, Xcode 16, Swift Package Manager, app lifecycle and background processing.
• SwiftUI: state management with @State, @Binding, @ObservedObject and @StateObject, Combine, custom view modifiers, navigation and coordinator patterns, previews, accessibility-first development and performance.
• UIKit and legacy: interoperability, wrapping UIViewController and UIView, Auto Layout, diffable data sources and migration to SwiftUI.
• Architecture: MVVM, Clean Architecture, coordinator and repository patterns, dependency injection with Swinject or custom solutions, and modular Swift packages.
• Data and networking: Core Data with @FetchRequest, SwiftData, CloudKit, Keychain, URLSession with async/await, Codable REST, GraphQL with Apollo iOS, WebSocket, certificate pinning and offline-first caching.
• Performance, security and testing: Instruments profiling, image caching with SDWebImage or Kingfisher, biometric authentication, App Transport Security, App Tracking Transparency, XCTest, XCUITest, snapshot tests and Xcode Cloud.
• Distribution and ecosystem: App Store Connect, review guidelines, ASO, TestFlight, Fastlane, GitHub Actions, Bitrise, Crashlytics, Sentry, widgets, Live Activities, SiriKit, Core ML, ARKit, HealthKit, watchOS, Catalyst and Sign in with Apple.
• Accessibility: VoiceOver, Dynamic Type, reduced motion, accessibility audits and Voice Control.

Use it for iOS developer tasks and for guidance, best practices or checklists on native iOS development. Do not use it when the task is unrelated to iOS development or needs a different domain or tool. The limitations note that output is not a substitute for environment-specific validation, testing or expert review, and that the assistant should ask for clarification when inputs or success criteria are missing.

The input is an iOS development requirement. The skill's response approach has eight steps: analyze requirements for iOS-specific patterns, recommend SwiftUI-first solutions with UIKit integration when needed, provide production-ready Swift code with error handling, include accessibility from the design phase, consider App Store guidelines, optimize for performance across device types, implement testing strategies and address privacy and security proactively.

Example requests it lists include building a SwiftUI app with Core Data and CloudKit synchronization, creating custom UIKit components that integrate with SwiftUI, implementing biometric authentication with fallback handling, designing an accessible data visualization with VoiceOver support, setting up CI/CD with Xcode Cloud and TestFlight, optimizing performance with Instruments, creating Live Activities for lock screen updates and implementing ARKit for product visualization.

Its behavioral traits include following the Human Interface Guidelines closely, using Swift's type system for compile-time safety, planning for multiple device sizes and orientations, and following App Store review guidelines proactively. Detailed examples are in resources/implementation-playbook.md.

The skill covers Apple frameworks and services (SwiftUI, UIKit, Core Data, SwiftData, CloudKit, HealthKit, HomeKit, ARKit, Core ML) and third-party tools such as Swinject, Apollo iOS, SDWebImage, Kingfisher, Fastlane, Bitrise, Crashlytics and Sentry.

It is for iOS engineers and teams building native apps who want SwiftUI-first, production-ready code with accessibility, security and App Store compliance considered from the start.