How to brief an AI agent to build version 1 of your iPhone app

Why version 1 has five screens

Version 1 does one job. Five screens are enough for someone to open the app, do the main thing and see the purchase screen. Everything else waits for version 2.

The narrower the brief, the less the agent has to guess. It doesn't spend time on accounts, feeds and sync nobody asked for, and it gets to a build you can open in the simulator sooner. That's why all 50 briefs in the Appto book start with a five-screen version 1 and spell out what it leaves out.

The seven parts of a brief

Every brief in the book follows the same order. Each part settles a question the agent would otherwise answer on its own, probably not the way you would.

1. What you're building and with what. One sentence. A native iPhone app in SwiftUI and the core idea in a few words.
2. Who it's for. One person with one job. A guitarist learning notes on the neck. A collector going through a box of cards.
3. How it differs from named leaders. Two or three apps by name and three or four concrete differences. The agent gets a target, and the app doesn't come out as a copy of the leader.
4. The five screens of version 1. Screen names in the order a person sees them.
5. What version 1 leaves out. An explicit list. Without it the agent adds extras with good intentions.
6. Money. What's free, what's paid, one purchase or a subscription, ads or none.
7. What to check before you start. Whether the name is free on the App Store, where the data comes from, whether anyone else holds rights to the content.

Sometimes there's an eighth line about content. For a party game it's 600 to 900 cards across 8 to 12 decks that you write yourself, with no photos or camera. For a weekly meal planner it's no recipe database, people enter their own dishes (Appto book, October 13, 2026).

A full example. A guitar fretboard trainer

Here is the brief for niche 01 from the book, line by line.

Part	Line of the brief from the book
What and on what	Build a native iPhone app in SwiftUI: an interactive guitar fretboard trainer.
Who it's for	Guitarists learning notes, scales and chords on the neck.
How it differs from Solo, Ultimate Guitar and Fretonomy	Timed drills like "find C# on the 5th string", a score by fretboard zone, any tuning, fully offline, no account.
Version 1, five screens	Fretboard, scale and chord picker, timed drill, progress by zone, settings with tunings.
Not in version 1	Songs, tabs, social features.
Money	One purchase or a yearly Pro plan, no ads.
Before you start	Check that the app name is free on the App Store.

Appto book 50 iPhone app niches, niche 01, October 13, 2026 edition.

Seven lines, and the agent has little room to guess. It knows who the app is for, what it will be compared with, which screens to draw and what to leave alone. The money and the market in this niche are covered in the guitar fretboard trainer write-up.

What to leave out of a brief

• "Make it like the leader." Name the differences in words. One more lookalike with a new icon gets lost among the others.
• Other companies' trademarks in the name. Pokémon and Magic don't belong in the name or subtitle of a card scanner, even if some competitors put them there.
• Other people's content. Recipes on other sites are copyrighted. Bible translations have to be public domain, such as KJV and WEB; NIV and ESV are licensed (Appto book).
• Everything at once. Move accounts, feeds, chat and sync to version 2.
• Promises the app won't keep. In astrology, interpretations are framed as something to reflect on, never as predictions.
• Passwords and keys. A brief doesn't need them.

What to check before you start

The last line of the brief is the shortest, and the most expensive to skip. Examples from the book (October 13, 2026 edition).

• The name. Verseful and VerseMark are taken in Bible verse memorization, Vaulty is taken for a photo vault, Sweepshot is taken twice. The word charades is overcrowded in search.
• The data. For Magic cards there's the open Scryfall database, which Appto checked on September 24, 2026. Some Open Library editions have no ISBN, so adding a book by hand has to be a full path.
• Calculation accuracy. An astrology app's planet positions get checked against a published ephemeris before any screens are built.
• Season. Yearly reading goals are set in January, so a reading tracker's launch should be planned around that.

How to steer the agent after version 1

Once the first build is ready, the editing begins. This is where a human eye matters.

• Look at every screen. The agent checks the screens in the simulator, and a human eye catches what a check can't. In Appto a step gets its checkmark only after an actual build and check.
• One change per screen. Be specific about where. "On the drill screen the timer is too small, make it bigger and move it to the top." In Appto you can pin a note right on the screen mockup.
• New ideas go on the version 2 list. The App Store and the first purchases come first.

The whole path from brief to App Store is in how to build an iOS app with AI, and the release itself in how to publish an app on the App Store.

Where to get ready briefs

The book 50 iPhone app niches has 50 ready briefs for an agent, one per niche, next to the niche's revenue, leaders and their weak spots. Five niches with their briefs are free, including the guitar fretboard trainer and the party game on one phone.

A brief goes into Claude Code, Codex or Appto.