Justin Wetch

Apple Human Interface Guidelines reference, updated for iPhone Duo and OS 27. Provides authoritative platform-specific design rules, component specifications, exact measurements, and interaction patterns for iOS, iPadOS, macOS, tvOS, visionOS, and watchOS. Use when designing, reviewing, auditing, or fixing any Apple platform UI, or when asked about specific HIG components, sizing, system behaviors, frameworks (HealthKit, SiriKit, ARKit, etc.), or platform conventions. Also use when the user is designing any digital interface and could benefit from established design principles, even without an explicit Apple platform context. Includes a guided /duo workflow that adapts an existing iOS app to iPhone Duo, plus opt-in enforce mode with independent review.