Mobile Design Skill
When to Use This Skill
Use this skill when working on:
- Mobile-First Web Applications: Building responsive websites that prioritize mobile user experience
- Native Mobile Apps: Designing iOS or Android applications with platform-specific patterns
- Progressive Web Apps (PWAs): Creating app-like experiences in the browser
- Hybrid Mobile Applications: Developing cross-platform apps using React Native, Flutter, or similar frameworks
- Responsive Design Systems: Creating components that adapt seamlessly across devices
- Touch-First Interfaces: Designing for touchscreen interactions rather than mouse/keyboard
- Mobile E-commerce: Building shopping experiences optimized for small screens
- Mobile Dashboards: Adapting data-heavy interfaces for mobile consumption
- Gesture-Based Interfaces: Implementing swipe, pinch, and other touch gestures
- Accessibility Audits: Ensuring mobile interfaces meet accessibility standards
This skill helps you create mobile experiences that feel native, perform well, and delight users on smartphones and tablets.
Core Concepts
Mobile-First Design Philosophy
Mobile-first design starts with the smallest screen and progressively enhances for larger devices:
Why Mobile-First?
- Forces prioritization of essential content and features
- Improves performance by default (lighter assets, simpler layouts)
- Easier to scale up than scale down
- Reflects actual user behavior (mobile traffic often exceeds desktop)
- Ensures core functionality works on all devices
Mobile-First vs Desktop-First:
Touch Targets and Ergonomics
Minimum Touch Target Sizes:
- Apple: 44×44 points (iOS Human Interface Guidelines)
- Google: 48×48 dp (Material Design)
- Microsoft: 40×40 pixels (Windows Phone)
- Recommended: 48×48 pixels minimum, 56×56 pixels optimal
Touch Target Spacing:
- Minimum 8px spacing between interactive elements
- Optimal 12-16px spacing for frequently used controls
- Edge-to-edge buttons can touch if they're different types (e.g., cancel vs confirm)
Thumb Zones:
Mobile screens have three ergonomic zones:
- Easy Zone (Green): Bottom third, center - easiest to reach with thumb
- Stretch Zone (Yellow): Middle area - requires slight reach
- Difficult Zone (Red): Top corners - hardest to reach one-handed
Design Implications:
- Place primary actions in the easy zone (bottom center)
- Put destructive actions in difficult zones (top corners)
- Navigation typically at top or bottom, never middle
- Consider both left-handed and right-handed users
Viewport and Screen Considerations
Common Mobile Breakpoints:
Viewport Meta Tag:
Safe Areas (iPhone X and later):
Touch Interactions
Tap (Primary Interaction)
Single Tap:
- Primary action on buttons, links, list items
- Should provide immediate visual feedback (0-100ms delay)
- Minimum size: 48×48 pixels
Double Tap:
- Zoom in/out (maps, images)
- Like/favorite (Instagram, Twitter)
- Less common, use sparingly
iOS Double-Tap Zoom Prevention:
Swipe Gestures
Horizontal Swipe:
- Navigate between screens/pages
- Reveal actions (swipe-to-delete, swipe-to-archive)
- Dismiss cards/modals
- Switch tabs
Vertical Swipe:
- Pull to refresh (downward swipe from top)
- Scroll content
- Dismiss bottom sheets/modals (downward swipe)
Pinch and Spread (Zoom)
Used for:
- Image galleries
- Maps
- PDF viewers
- Any zoomable content
Long Press
Used for:
- Context menus
- Item selection mode
- Drag-and-drop initiation
- Additional options
Drag and Drop
Navigation Patterns
Tab Bar Navigation
Bottom Tab Bar (iOS standard, Android common):
Best Practices:
- 3-5 tabs maximum
- Always show labels (don't rely on icons alone)
- Highlight active tab clearly
- Keep tabs visible at all times
- Most important section on the left (for LTR languages)
Hamburger Menu (Drawer Navigation)
When to Use:
- Secondary navigation
- Many navigation options (6+)
- Infrequently accessed features
- Settings and account options
Avoid When:
- Primary navigation is needed
- User needs quick access to all sections
- You have 5 or fewer main sections (use tabs instead)
Bottom Sheets and Modals
Bottom Sheet (Material Design):
Full-Screen Modal:
Stack Navigation
Mobile UI Components
Cards
Material Design Card:
Lists
iOS-Style List:
Forms
Mobile-Optimized Form:
Input Types for Mobile Keyboards:
Action Sheets
Platform Conventions
iOS Human Interface Guidelines
Navigation Bar:
- Height: 44pt (plus status bar)
- Large title: 52pt collapsible header
- Back button always shows previous screen title
- Right-aligned action buttons
Tab Bar:
- Height: 49pt (plus safe area)
- 5 tabs maximum
- Badge notifications on tab icons
- Selected tab uses accent color
Typography:
- SF Pro (system font)
- Dynamic Type support required
- Font sizes: 11pt to 34pt
- Weight hierarchy: Regular, Medium, Semibold, Bold
Colors:
- System colors adapt to light/dark mode
- Blue (#007AFF) for tappable elements
- Red (#FF3B30) for destructive actions
- Semantic colors: label, secondaryLabel, tertiaryLabel
Spacing:
- Minimum margins: 16pt
- Standard spacing: 8pt, 16pt, 24pt, 32pt
- Component padding: 16pt horizontal, 12pt vertical
Material Design (Android)
App Bar:
- Height: 56dp (64dp for tablets)
- Elevation: 4dp
- Hamburger icon or back arrow on left
- Title centered or left-aligned
- Action icons on right (max 3)
Bottom Navigation:
- Height: 56dp
- 3-5 destinations
- Icons with text labels
- Active indicator
FAB (Floating Action Button):
- Size: 56×56dp (regular), 40×40dp (mini)
- Position: 16dp from edges
- Primary action only
- Extended FAB includes text label
Typography:
- Roboto font family
- Scale: 12sp to 96sp
- Line height: 1.5× font size
- Letter spacing varies by size
Elevation:
- Shadow depth indicates hierarchy
- 0dp: flat surface
- 1-8dp: raised components
- 16-24dp: modals and dialogs
Spacing:
- 4dp grid system
- Keylines: 16dp, 72dp from edges
- Component spacing: 8dp, 16dp, 24dp
Accessibility
Touch Target Sizes
WCAG 2.1 Level AAA:
- Minimum: 44×44 pixels
- Recommended: 48×48 pixels or larger
- Spacing: 8px minimum between targets
Screen Reader Support
Semantic HTML:
React Native Accessibility:
Color Contrast
WCAG AA Requirements:
- Normal text: 4.5:1 contrast ratio
- Large text (18pt+): 3:1 contrast ratio
- UI components: 3:1 contrast ratio
Focus Indicators
Performance
Image Optimization
Responsive Images:
Lazy Loading:
Loading Strategies
Skeleton Screens:
Progressive Web App (PWA):
Performance Metrics
Core Web Vitals for Mobile:
- LCP (Largest Contentful Paint): < 2.5s
- FID (First Input Delay): < 100ms
- CLS (Cumulative Layout Shift): < 0.1
Responsive Breakpoints
Common Device Widths
Orientation-Specific Styles
Container Queries (Modern Approach)
Examples
1. Mobile E-commerce Product List
2. Infinite Scroll Feed
3. Mobile Search with Autocomplete
4. Filter Drawer
5. Mobile Payment Form
6-20. Additional Examples
For brevity, here are summaries of 14 more essential mobile design patterns:
6. Sticky Header with Scroll Progress
- Header shrinks on scroll
- Progress bar shows reading position
- Back-to-top button appears after scroll
7. Image Gallery with Pinch Zoom
- Full-screen image viewer
- Swipe between images
- Pinch to zoom functionality
8. Mobile-Optimized Data Table
- Horizontal scroll with sticky first column
- Card view on small screens
- Expandable rows for details
9. Bottom Sheet Menu
- Swipe up to expand
- Drag to dismiss
- Multiple snap points (collapsed, half, full)
10. Mobile Calendar Picker
- Month view optimized for touch
- Date range selection
- Quick actions (Today, Tomorrow, Next Week)
11. Floating Action Button (FAB) with Speed Dial
- Primary action always visible
- Expands to show related actions
- Smooth animations
12. Pull to Refresh
- Custom loading animation
- Haptic feedback
- Success/error states
13. Swipeable Tabs
- Horizontal scroll tabs
- Active tab indicator
- Snap to tab on scroll
14. Mobile Video Player
- Custom controls optimized for touch
- Picture-in-picture mode
- Gesture controls (tap to pause, double-tap to skip)
15. Mobile Toast Notifications
- Non-intrusive messaging
- Auto-dismiss with manual override
- Action buttons
16. Collapsible Accordion
- Touch-friendly expand/collapse
- Smooth animations
- Multiple sections
17. Mobile Stepper Form
- Multi-step process
- Progress indicator
- Back/Next navigation
18. Voice Input Interface
- Microphone button
- Real-time transcription
- Voice feedback
19. Onboarding Carousel
- Swipeable introduction screens
- Skip option
- Progress dots
20. Mobile Share Sheet
- Native-like sharing interface
- Common share targets
- Copy link functionality
Conclusion
Mobile design requires deep understanding of touch interactions, platform conventions, and performance optimization. By following mobile-first principles, respecting thumb zones, and implementing platform-appropriate patterns, you create experiences that feel natural and performant on mobile devices.
Remember: mobile users are often on-the-go, have limited attention, and expect instant responsiveness. Prioritize speed, clarity, and ease of use above all else.

