App Store Screenshots Agent Skill

> Install the belt CLI skill: npx skills add belt-sh/cli

App Store Screenshots

Create app store screenshots and preview videos via inference.sh CLI.

Quick Start

> Requires inference.sh CLI (belt). Install instructions

belt login

# Generate a device mockup scene
belt app run falai/flux-dev-lora --input '{
  "prompt": "iPhone 15 Pro showing a clean modern app interface with analytics dashboard, floating at slight angle, soft gradient background, professional product photography, subtle shadow, marketing mockup style",
  "width": 1024,
  "height": 1536
}'

Platform Specifications

Apple App Store (iOS)

| Device | Dimensions (px) | Required |

|--------|-----------------|----------|

| iPhone 6.7" (15 Pro Max) | 1290 x 2796 | Required |

| iPhone 6.5" (11 Pro Max) | 1284 x 2778 | Required |

| iPhone 5.5" (8 Plus) | 1242 x 2208 | Optional |

| iPad Pro 12.9" (6th gen) | 2048 x 2732 | If iPad app |

| iPad Pro 11" | 1668 x 2388 | If iPad app |

• Up to 10 screenshots per localization
• First 3 screenshots are visible without scrolling (critical)
• Formats: PNG or JPEG (no alpha/transparency for JPEG)

Google Play Store (Android)

| Spec | Value |

|------|-------|

| Min dimensions | 320 px (any side) |

| Max dimensions | 3840 px (any side) |

| Aspect ratio | 16:9 or 9:16 |

| Max screenshots | 8 per device type |

| Formats | PNG or JPEG (24-bit, no alpha) |

• Feature graphic: 1024 x 500 px (required for featuring)
• Promo video: YouTube URL (optional but recommended)

The First 3 Rule

80% of App Store impressions show only the first 3 screenshots (before the user scrolls). These three must:

• Communicate the core value proposition
• Show the best feature/outcome
• Differentiate from competitors

Screenshot Gallery Order

| Position | Content | Purpose |

|----------|---------|---------|

| 1 | Hero — core value, best feature | Stop the scroll, communicate what the app does |

| 2 | Key differentiator | What makes you unique vs competitors |

| 3 | Most popular feature | The thing users love most |

| 4 | Social proof or outcome | Ratings, results, testimonials |

| 5-8 | Additional features | Supporting features, settings, integrations |

| 9-10 | Edge cases | Specialized features for niche users |

Screenshot Styles

1. Device Frame with Caption

The standard: device mockup showing the app, caption text above/below.

┌──────────────────────────┐
│   "Track Your Habits     │  ← Caption (benefit-focused)
│    Effortlessly"         │
│                          │
│   ┌──────────────────┐   │
│   │                  │   │
│   │   App Screen     │   │  ← Actual app UI in device frame
│   │   Content        │   │
│   │                  │   │
│   │                  │   │
│   └──────────────────┘   │
│                          │
└──────────────────────────┘

2. Full-Bleed UI (No Device Frame)

The app UI fills the entire screenshot. Works for immersive apps.

3. Lifestyle Context

The device shown in a real-world context (person holding phone, on desk, etc.).

4. Feature Highlight with Callouts

UI screenshot with arrows/circles pointing to specific features.

Caption Writing

Rules

• Max 2 lines of text
• Benefit-focused, not feature-focused
• 30pt+ equivalent font size (must be readable in store)

Examples

❌ Feature-focused:
"Push Notification System"
"Calendar View with Filters"
"Data Export Functionality"

✅ Benefit-focused:
"Never Miss a Deadline Again"
"See Your Week at a Glance"
"Share Reports in One Tap"

Generating Screenshots

Hero Screenshot (Position 1)

# Clean device mockup with hero feature
belt app run falai/flux-dev-lora --input '{
  "prompt": "modern iPhone showing a beautiful fitness tracking app with activity rings and workout summary, device floating at slight angle against soft purple gradient background, professional product shot, clean minimal composition, subtle reflection",
  "width": 1024,
  "height": 1536
}'

Feature Highlight

# Feature callout style
belt app run bytedance/seedream-4-5 --input '{
  "prompt": "app store screenshot style, iPhone showing a messaging app with AI writing suggestions highlighted, clean white background, subtle UI callout arrows, professional marketing asset, modern design",
  "size": "2K"
}'

Lifestyle Context

# Device in real-world setting
belt app run falai/flux-dev-lora --input '{
  "prompt": "person holding iPhone showing a cooking recipe app, kitchen background with ingredients, warm natural lighting, over-the-shoulder perspective, lifestyle photography, authentic feeling",
  "width": 1024,
  "height": 1536
}'

Before/After

# Split comparison
belt app run infsh/stitch-images --input '{
  "images": ["before-screenshot.png", "after-screenshot.png"],
  "direction": "horizontal"
}'

Preview Videos

Apple App Store

| Spec | Value |

|------|-------|

| Duration | 15-30 seconds |

| Orientation | Portrait or landscape (match app) |

| Audio | Optional (loops silently in store) |

| Format | H.264, .mov or .mp4 |

Google Play

| Spec | Value |

|------|-------|

| Source | YouTube URL |

| Duration | 30s-2min recommended |

| Orientation | Landscape preferred |

Preview Video Structure

| Segment | Duration | Content |

|---------|----------|---------|

| Hook | 0-3s | Show the core outcome/wow moment |

| Feature 1 | 3-10s | Demonstrate top feature in action |

| Feature 2 | 10-18s | Second key feature |

| Feature 3 | 18-25s | Third feature or social proof |

| CTA | 25-30s | End screen with app icon |

# Generate preview video scenes
belt app run google/veo-3-1-fast --input '{
  "prompt": "smooth screen recording style, finger tapping on a modern mobile app interface, swiping between screens showing charts and data visualizations, clean UI transitions, professional app demo"
}'

Localization

Each language gets its own set of screenshots. Priorities:

| Market | Localization Level |

|--------|-------------------|

| Primary markets | Full: new screenshots + translated captions |

| Secondary markets | Translated captions, same screenshots |

| Other | English defaults |

Key localization markets: English, Japanese, Korean, Chinese (Simplified), German, French, Spanish, Portuguese (Brazilian)

A/B Testing (Google Play)

Google Play Console supports store listing experiments:

• Test different screenshot orders
• Test with/without device frames
• Test different captions
• Test different color schemes
• Run for 7+ days with 50%+ traffic for significant results

Common Mistakes

| Mistake | Problem | Fix |

|---------|---------|-----|

| Settings screen as screenshot | Nobody cares about settings | Show core value, not infrastructure |

| Onboarding flow screenshots | Shows friction, not value | Show the app in-use state |

| Too much text | Unreadable in store | Max 2 lines, 30pt+ font |

| Wrong dimensions | Rejected by store | Use exact platform specs |

| All screenshots look the same | No reason to scroll | Vary composition and content |

| Feature-focused captions | Doesn't communicate benefit | "Never Miss a Deadline" > "Push Notifications" |

| Outdated UI | Looks abandoned | Update screenshots with each major release |

| No hero screenshot | Weak first impression | Position 1 = your best shot |

Checklist

• [ ] Correct dimensions for target platform
• [ ] First 3 screenshots communicate core value
• [ ] Captions are benefit-focused, max 2 lines
• [ ] No onboarding or settings screens
• [ ] Preview video is 15-30s with hook in first 3s
• [ ] Localized for top markets
• [ ] Feature graphic (1024x500) for Google Play
• [ ] Screenshots updated for current app version
• [ ] A/B test variant prepared

Related Skills

npx skills add inference-sh/skills@ai-image-generation
npx skills add inference-sh/skills@ai-video-generation
npx skills add inference-sh/skills@image-upscaling
npx skills add inference-sh/skills@prompt-engineering

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