Mobile-app UGC Format: holiday app ads vs App Store previews

What the Format is for

Call sume-mobile-app-ugc when you want a creator-style ad for an app: someone relatable, a visible phone, and one clear benefit or reaction. The catalog describes it as a finished mobile-app UGC video "with a relatable creator, a visible phone, and a clear app benefit or reaction", for consumer app testimonials, app discovery hooks, phone demonstrations and creator-led SaaS ads.

That is an ad, not an App Store asset. Apple's own specification for App Previews is stricter and different, so treat the Format's output as a paid-social creative and build the store preview separately if you need one.

The two deliverables side by side

Apple's App Store Connect help page lists the App Preview limits. The TikTok in-feed page lists the ad limits. The two overlap only in the file families (.mp4 and .mov) and not in duration, so one clip rarely serves both without a cut.

Run it with the holiday angle in the instruction

Seasonal context belongs in instruction and input, which the run reads after the Format's own recipe, so where they disagree your instruction wins. A holiday app ad usually needs one reaction line and one screen moment: for example a gift-tracking or savings app, shown on a phone in a busy shop.

Keep your own identifiers on your side, keyed by run.id or the Idempotency-Key you sent. Set generation_spend_cap_usd per run so a retry loop cannot exceed what you planned.

curl -sS -X POST "https://api.sume.com/v1/formats/sume/sume-mobile-app-ugc/runs" \
  -H "Authorization: Bearer $SUME_API_KEY" \
  -H "Content-Type: application/json" \
  -H "Idempotency-Key: giftlist-app-holiday-1" \
  -d '{
    "instruction": "Vertical 9:16. Creator in a busy shop shows the gift list screen on her phone and reacts to the total.",
    "input": { "app_name": "Giftlist", "benefit": "one list for every gift" },
    "generation_spend_cap_usd": 40
  }'

What to put in the brief

A holiday app ad works when the benefit is stated once and shown once. Give the Format a single sentence of benefit, the audience, and the season hook in instruction; leave the screen contents to a single screenshot or description in input. Avoid listing five features, because a creator-style clip reads as one reaction, not a feature tour.

Useful seasonal hooks for apps include year-end budgeting, gift lists, travel bookings for the holidays, and a new-year habit start. Pick one per run and keep the offer or trial wording factual and short.

Cut a store-length version

If you want to reuse a moment for an App Preview, take a 15 to 30 second range with Video trim, then run Video inspect to read the probe of the cut before you upload anything. Verify frame rate and container against Apple's table; do not assume a generated file meets them.

The Format API page has no field that sets duration or frame rate for a catalog Format, so these constraints are checks on the output, not inputs to the run.