ios-application-dev
iOS application development guide covering UIKit, SnapKit, and SwiftUI. Includes touch targets, safe areas, navigation patterns, Dynamic Type, Dark Mode, accessibility, collection views, common UI components, and SwiftUI design guidelines. For detailed references on specific topics, see the reference files. Use when: developing iOS apps, implementing UI, reviewing iOS code, working with UIKit/SnapKit/SwiftUI layouts, building iPhone interfaces, Swift mobile development, Apple HIG compliance, iOS accessibility implementation.
What this skill does
# iOS Application Development Guide A practical guide for building iOS applications using UIKit, SnapKit, and SwiftUI. Focuses on proven patterns and Apple platform conventions. ## Quick Reference ### UIKit | Purpose | Component | |---------|-----------| | Main sections | `UITabBarController` | | Drill-down | `UINavigationController` | | Focused task | Sheet presentation | | Critical choice | `UIAlertController` | | Secondary actions | `UIContextMenuInteraction` | | List content | `UICollectionView` + `DiffableDataSource` | | Sectioned list | `DiffableDataSource` + `headerMode` | | Grid layout | `UICollectionViewCompositionalLayout` | | Search | `UISearchController` | | Share | `UIActivityViewController` | | Location (once) | `CLLocationButton` | | Feedback | `UIImpactFeedbackGenerator` | | Linear layout | `UIStackView` | | Custom shapes | `CAShapeLayer` + `UIBezierPath` | | Gradients | `CAGradientLayer` | | Modern buttons | `UIButton.Configuration` | | Dynamic text | `UIFontMetrics` + `preferredFont` | | Dark mode | Semantic colors (`.systemBackground`, `.label`) | | Permissions | Contextual request + `AVCaptureDevice` | | Lifecycle | `UIApplication` notifications | ### SwiftUI | Purpose | Component | |---------|-----------| | Main sections | `TabView` + `tabItem` | | Drill-down | `NavigationStack` + `NavigationPath` | | Focused task | `.sheet` + `presentationDetents` | | Critical choice | `.alert` | | Secondary actions | `.contextMenu` | | List content | `List` + `.insetGrouped` | | Search | `.searchable` | | Share | `ShareLink` | | Location (once) | `LocationButton` | | Feedback | `UIImpactFeedbackGenerator` | | Progress (known) | `ProgressView(value:total:)` | | Progress (unknown) | `ProgressView()` | | Dynamic text | `.font(.body)` semantic styles | | Dark mode | `.primary`, `.secondary`, `Color(.systemBackground)` | | Scene lifecycle | `@Environment(\.scenePhase)` | | Reduce motion | `@Environment(\.accessibilityReduceMotion)` | | Dynamic type | `@Environment(\.dynamicTypeSize)` | ## Core Principles ### Layout - Touch targets >= 44pt - Content within safe areas (SwiftUI respects by default, use `.ignoresSafeArea()` only for backgrounds) - Use 8pt spacing increments (8, 16, 24, 32, 40, 48) - Primary actions in thumb zone - Support all screen sizes (iPhone SE 375pt to Pro Max 430pt) ### Typography - UIKit: `preferredFont(forTextStyle:)` + `adjustsFontForContentSizeCategory = true` - SwiftUI: semantic text styles `.headline`, `.body`, `.caption` - Custom fonts: `UIFontMetrics` / `Font.custom(_:size:relativeTo:)` - Adapt layout at accessibility sizes (minimum 11pt) ### Colors - Use semantic system colors (`.systemBackground`, `.label`, `.primary`, `.secondary`) - Asset catalog variants for custom colors (Any/Dark Appearance) - No color-only information (pair with icons or text) - Contrast ratio >= 4.5:1 for normal text, 3:1 for large text ### Accessibility - Labels on icon buttons (`.accessibilityLabel()`) - Reduce motion respected (`@Environment(\.accessibilityReduceMotion)`) - Logical reading order (`.accessibilitySortPriority()`) - Support Bold Text, Increase Contrast preferences ### Navigation - Tab bar (3-5 sections) stays visible during navigation - Back swipe works (never override system gestures) - State preserved across tabs (`@SceneStorage`, `@State`) - Never use hamburger menus ### Privacy & Permissions - Request permissions in context (not at launch) - Custom explanation before system dialog - Support Sign in with Apple - Respect ATT denial ## Checklist ### Layout - [ ] Touch targets >= 44pt - [ ] Content within safe areas - [ ] Primary actions in thumb zone (bottom half) - [ ] Flexible widths for all screen sizes (SE to Pro Max) - [ ] Spacing aligns to 8pt grid ### Typography - [ ] Semantic text styles or UIFontMetrics-scaled custom fonts - [ ] Dynamic Type supported up to accessibility sizes - [ ] Layouts reflow at large sizes (no truncation) - [ ] Minimum text size 11pt ### Colors - [ ] Semantic system colors or light/dark asset variants - [ ] Dark Mode is intentional (not just inverted) - [ ] No color-only information - [ ] Text contrast >= 4.5:1 (normal) / 3:1 (large) - [ ] Single accent color for interactive elements ### Accessibility - [ ] VoiceOver labels on all interactive elements - [ ] Logical reading order - [ ] Bold Text preference respected - [ ] Reduce Motion disables decorative animations - [ ] All gestures have alternative access paths ### Navigation - [ ] Tab bar for 3-5 top-level sections - [ ] No hamburger/drawer menus - [ ] Tab bar stays visible during navigation - [ ] Back swipe works throughout - [ ] State preserved across tabs ### Components - [ ] Alerts for critical decisions only - [ ] Sheets have dismiss path (button and/or swipe) - [ ] List rows >= 44pt tall - [ ] Destructive buttons use `.destructive` role ### Privacy - [ ] Permissions requested in context (not at launch) - [ ] Custom explanation before system permission dialog - [ ] Sign in with Apple offered with other providers - [ ] Basic features usable without account - [ ] ATT prompt shown if tracking, denial respected ### System Integration - [ ] App handles interruptions gracefully (calls, background, Siri) - [ ] App content indexed for Spotlight - [ ] Share Sheet available for shareable content ## References | Topic | Reference | |-------|-----------| | Touch Targets, Safe Area, CollectionView | [Layout System](references/layout-system.md) | | TabBar, NavigationController, Modal | [Navigation Patterns](references/navigation-patterns.md) | | StackView, Button, Alert, Search, ContextMenu | [UIKit Components](references/uikit-components.md) | | CAShapeLayer, CAGradientLayer, Core Animation | [Graphics & Animation](references/graphics-animation.md) | | Dynamic Type, Semantic Colors, VoiceOver | [Accessibility](references/accessibility.md) | | Permissions, Location, Share, Lifecycle, Haptics | [System Integration](references/system-integration.md) | | Metal Shaders & GPU | [Metal Shader Reference](references/metal-shader.md) | | SwiftUI HIG, Components, Patterns, Anti-Patterns | [SwiftUI Design Guidelines](references/swiftui-design-guidelines.md) | | Optionals, Protocols, async/await, ARC, Error Handling | [Swift Coding Standards](references/swift-coding-standards.md) | --- Swift, SwiftUI, UIKit, SF Symbols, Metal, and Apple are trademarks of Apple Inc. SnapKit is a trademark of its respective owners.
Related in Design
contribute
IncludedLocal-only OSS contribution command center. Auto-refreshes the user's in-flight PR and issue state on invoke so conversations start with full context — no need to brief Claude on what's in flight. Helps the user find issues to contribute to on GitHub, builds per-repo dossiers of what each upstream expects (CLA, DCO, branch convention, AI policy, draft-first, review bots, issue templates), runs deterministic gates before any external action so AI-assisted contributions don't reach maintainers as slop. State is markdown-only: candidate files at ~/.contribute-system/candidates/, repo dossiers at ~/.contribute-system/research/, append-only event log at ~/.contribute-system/log.jsonl. No database, no cloud calls. Use when the user asks about their PRs / issues / contributions, wants to find new work to take on, claim an issue, build/refresh a repo's dossier, or draft a Design Issue or PR. Trigger with "/contribute", "what's my PR status", "find a contribution", "claim issue X", "draft a Design Issue for Y", "refresh dossier for Z".
architectural-analysis
IncludedUser-triggered deep architectural analysis of a codebase or scoped subtree across eight modes — information architecture, data flow, integration points, UI surfaces, interaction patterns, data model, control flow, and failure modes. This skill should be used when the user asks to "diagram this codebase," "map the architecture," "show the data flow," "give me an ERD," "trace control flow," "find the integration points," "verify the layout pattern," "audit the UX architecture," or any similar request whose primary deliverable is mermaid diagrams plus cited reports under docs/architecture/. Dispatches haiku/sonnet sub-agents in parallel for per-mode exploration, then verifies every citation mechanically before any node lands in a diagram. Not for one-off prose explanations of code (use code-explanation) or for high-level system design from scratch (use system-design).
mcp
IncludedModel Context Protocol (MCP) server development and tool management. Languages: Python, TypeScript. Capabilities: build MCP servers, integrate external APIs, discover/execute MCP tools, manage multi-server configs, design agent-centric tools. Actions: create, build, integrate, discover, execute, configure MCP servers/tools. Keywords: MCP, Model Context Protocol, MCP server, MCP tool, stdio transport, SSE transport, tool discovery, resource provider, prompt template, external API integration, Gemini CLI MCP, Claude MCP, agent tools, tool execution, server config. Use when: building MCP servers, integrating external APIs as MCP tools, discovering available MCP tools, executing MCP capabilities, configuring multi-server setups, designing tools for AI agents.
react-native-skia
IncludedDesign, build, debug, and optimise high-polish animated graphics in React Native or Expo using @shopify/react-native-skia, Reanimated, and Gesture Handler. Use when the user wants canvas-driven UI, shaders, paths, rich text, image filters, sprite fields, Skottie, video frames, snapshots, web CanvasKit setup, or performance tuning for custom motion-heavy elements such as loaders, hero art, cards, charts, progress indicators, particle systems, or gesture-driven surfaces. Also use when the user asks for fluid, glow, glass, blob, parallax, 60fps/120fps, or GPU-friendly animated effects in React Native, even if they do not explicitly say "Skia". Do not use for ordinary form/layout work with standard views.
plaid
IncludedProduct Led AI Development — guides founders from idea to launched product. Six capabilities: Idea (discover a product idea), Validate (pressure-test the idea against fatal flaws, problem reality, competition, and 2-week MVP feasibility), Plan (vision intake + document generation), Design (translate image references into a design.md spec), Launch (go-to-market strategy), and Build (roadmap execution). Use when someone says "PLAID", "plaid idea", "help me find an idea", "product idea", "idea from my business", "idea from my expertise", "plaid validate", "validate my idea", "pressure-test", "is this idea good", "find fatal flaws", "validate the problem", "plan a product", "define my vision", "generate a PRD", "product strategy", "plaid design", "design from image", "translate image to design", "create design.md", "extract design tokens", "plaid launch", "go-to-market", "launch plan", "GTM strategy", "launch playbook", "plaid build", "build the app", "start building", or "execute the roadmap".
nextjs-framer-motion-animations
IncludedAdds production-safe Motion for React or Framer Motion animations to Next.js apps, including reveal, hover and tap micro-interactions, whileInView, stagger, AnimatePresence, layout and layoutId transitions, reorder, scroll-linked UI, and lightweight route-content transitions. Use when the user asks to add, refactor, or debug Motion or Framer Motion in App Router or Pages Router codebases, especially around server/client boundaries, reduced motion, LazyMotion, bundle size, hydration, or route transitions. Avoid for GSAP-style timelines, WebGL or 3D scenes, heavy scroll storytelling, or CSS-only effects unless Motion is explicitly requested.