What this guide helps you make

By the end of this guide you will have a real phone app, made by you, listed on the App Store, on Google Play, or both, for anyone to download. Not a demo. Not a template someone else filled in. Your own app, with your name on it.

It can be whatever your card life needs. A tracker for your own collection that shows what every card is worth. A tool for selling at weekend shows: your stock, a deal screen you can turn toward a customer, a total at the end of the day. An app for your shop, with your stock, your prices and your name on it. The guide uses one small example app all the way through, and you build your own next to it.

You get there in stages. In the first days, a first screen of your app runs on your own phone. A couple of weeks later, friends test it on theirs. Then you polish it, add accounts, set up payment if you want it, and send it to Apple or Google for review.

Who builds it

You do not need to know how to program. Claude is an AI made by a company called Anthropic. You describe what you want in plain words, and Claude writes the code: the instructions a phone follows. You look at the result on your phone and say what to change. Claude changes it. Round and round, one small step at a time.

Your job is everything Claude cannot do. You decide what the app is for. You judge whether it feels right. You test it on a real phone, keep backups, handle the accounts and the money, and follow Apple's and Google's rules. This guide teaches each of those from zero.

Claude is a tool, not a person. It makes mistakes, sometimes confident ones. Things will break along the way. That is normal, and the guide shows you how to notice and recover every time.

The example app: Binder

Every part of this guide uses the same made-up app, Binder. Binder keeps track of a card collection. You add a card with its set, number and condition, see what it is worth, see what the whole collection is worth, and keep a wishlist. That is the whole idea. It is small on purpose: small apps get finished. Scanning cards with the camera, live prices and tools for shows come later in the guide, after the small version works.

When you see Binder in an example, picture your own app in its place.

What this guide covers

• A computer: a Mac or a Windows PC. On a Mac, Apple's own tools build the iPhone version. On a Windows PC, an online service builds it for you. Both paths are in this guide; the next step explains the differences.
• Apps for the iPhone, for Android phones, or for both. One app, built once, runs on both kinds of phone. You pick your phones once, and the guide shows only your steps.
• One person, or a small team, building something useful. Big games with 3D graphics need other tools.

The first parts are free: computer basics, meeting Claude, planning your app, setting up your tools, and your first screen on your phone. The paid parts take you the rest of the way: building your card app, working safely, accounts and a server, card data and other outside services, prices, deals and shows, the developer programs, a website, getting paid, launch, and life after launch.

Four questions before you start

Before step 1, the guide asks four short questions. Your answers decide which steps you see.

• Your app is for: iPhone, Android, or both. You see the steps for the phones you picked.
• Your computer: a Mac or a Windows PC. Every step then matches your keyboard and your screen.
• Have you used a computer before? Answer no, and Part 1 teaches the basics from the power button. Answer yes, and those steps are hidden, except three worth doing anyway: screenshots, strong passwords and updates.
• Do you have the Claude app on your computer, with a paid plan? Answer yes, and Part 2 is hidden too, except its safety step, which everyone reads.

Nothing is final. Change any answer on the All steps page, linked at the top of every page, and the hidden steps come back.