Foundation Models On Device provides comprehensive integration patterns for Apple's on-device language model using the FoundationModels framework in iOS. It covers checking model availability, managing single-turn and multi-turn sessions, and utilizing the @Generable macro for structured data output. Developers can also implement custom tool calling for domain-specific tasks and perform snapshot streaming for real-time user interface updates. Reach for this skill when building privacy-preserving, offline-capable artificial intelligence features into iOS applications.