Designs App Store and Google Play screenshot sets to exact per-device store specs - with a runnable preflight validator, 3-6-word benefit-first caption bands, and a first-three sequence that reads as one pitch; the pixel specs themselves live in the body's store-facts block and are re-verified before shipping. Use when someone asks "design our App Store screenshots", "what size do Play Store screenshots need to be", "our store listing converts badly - redo the screenshots", or "write caption bands for our app screenshots". Do NOT use for listing titles, descriptions, or keywords - use app-store-copy instead; for signing, versioning, and submission mechanics, use app-store-release-prep; for the app preview video, use product-demo-director.
---
name: app-store-screenshot-designer
description: Designs App Store and Google Play screenshot sets to exact per-device store specs - with a runnable preflight validator, 3-6-word benefit-first caption bands, and a first-three sequence that reads as one pitch; the pixel specs themselves live in the body's store-facts block and are re-verified before shipping. Use when someone asks "design our App Store screenshots", "what size do Play Store screenshots need to be", "our store listing converts badly - redo the screenshots", or "write caption bands for our app screenshots". Do NOT use for listing titles, descriptions, or keywords - use app-store-copy instead; for signing, versioning, and submission mechanics, use app-store-release-prep; for the app preview video, use product-demo-director.
---
# app-store-screenshot-designer
Most store browsers never scroll past the third screenshot, and the install decision lands in seconds - practitioner-observed store behavior, stated here as the mechanism, not a statistic. Screenshots are the ad, not the documentation, and the costly mistake is spending slots 1-3 on a splash screen and an onboarding tour, then paying for the installs the listing itself repels. The stores punish a second failure just as reliably: off-spec files are rejected with zero tolerance, and under-spec sets are silently excluded from high-traffic promotional surfaces.
## Operating procedure
Run the steps in order: the spec table comes before any design, because a beautiful set at the wrong pixels is a rejected set; benefits are ranked before captions are written, because on a store listing the order IS the pitch.
### Step 1: Gather the charter and the benefit ranking
Ask for the client's charter block, in the format defined in premium-design-foundations. Paste the charter block if one exists. If the client has a charter but the foundations pack is not installed, elicit the needed values directly and label them provisional. If no charter exists at all, halt and route to premium-design-foundations - never substitute worked-example values. Then elicit:
1. **Platforms and device classes** shipping: App Store, Google Play, or both; phone and tablet coverage.
2. The **ranked benefit list**, strongest first - this ranking becomes the screenshot order, so ask for it as a ranking, not a feature dump.
3. Which screens **exist as real UI** and which are still mockups - real UI only; missing screens are flagged, never faked.
4. **Localization count** - every caption band multiplies by it.
5. **Social-proof assets** available: ratings, user counts, press lines, each with its date and source.
If any input is a guess, label it a guess and move on.