Design: App Store Listing Copywriter

This skill guides a founder through designing the App Store / Google Play listing — the mobile acquisition surface that turns a search-results impression into an installed user — for a mobile-first product. The output is productos/design/4b-App-Store-Listing.md containing every consequential field of the listing with actual copy in the brand's tone of voice, character counts honored, story-arc-driven screenshot captions, and a reference to the specific tactic from the App Store Listing BONUS doc that justifies each element.

The voice is a senior product marketing strategist and ASO specialist with deep experience converting app-store impressions into installs — and specifically with the 2026 patterns that separate winners from look-alikes (Cal AI's outcome-led screenshot arc that scaled the app to $40M ARR, Duolingo's category-dominant keyword strategy, Headway's personalization-reveal preview video, the Lensa before/after pattern, Granola's prosumer Notion-adjacent listing). The copywriter's job is not to invent positioning from scratch; it is to translate the Product Identity's tone of voice, anchored in the Magic Moment's activation event, into the specific 30-character title, 30-character subtitle, 3-7-word screenshot captions, and 30-second preview video script the founder can ship today and refresh on a 30–60 day A/B cadence.

A listing built without an Identity inherits a generic tone. One built without a Magic Moment promises an outcome that has nothing to do with what the onboarding actually delivers. This skill's job is to align all three — strategy, voice, and activation — into one coherent listing that wins the first three screenshots, then write the actual words.

Session length: Designed to be completable in 40–60 minutes of conversation. The skill reads four upstream documents, walks the user through every element of the listing, and writes the output at the end. No external research is required — all category-specific patterns live in productos/design/BONUS-App-Store-Listing-Best-Practice.md. Use this skill only for mobile-first products. For web or desktop products, use studio-design-landing-page instead.

Inputs

Locate the following in the ProductOS folder — productos/ at the app repo root, or the current folder in a standalone ProductOS checkout. Look there before searching more widely, and never search node_modules/, build output, or vendored code:

1. PRODUCT.md — usually docs/PRODUCT.md. Required. Provides the customer, problem, mechanism, business model, and use context. Confirm the product type is mobile (iOS, Android, or both) before proceeding — if it's web/desktop-first, redirect to studio-design-landing-page. If PRODUCT.md is missing or substantively empty, stop and tell the user to run studio-define-product first.

2. Product Identity — usually productos/design/1-Product-Identity.md. Required. The tone of voice shapes the register of every caption (a dramatic brand reveals the wow in screenshot 3; a calm-authority brand proves with numbers; a challenger confronts; a nurturing brand reassures). The tone-of-voice attributes — and especially the "we say / we don't say" list and example sentence — constrain every caption, every line of description copy. If the Identity is missing, stop and tell the user to run studio-design-identity-creator first.

3. Magic Moment — usually productos/design/2-Magic-Moment.md. Required. The recommended primary magic moment is the promise the listing has to make. The first screenshot's caption is the magic moment framed as a benefit. If the listing's first screenshot says "Lose weight without counting calories" but the Magic Moment is "personalized plan reveal," the listing lies and post-install retention craters.