The first version: must-have and later lists

By the endYou have a must-have list of 3 to 5 things and a later list for everything else.

Your first version is the smallest app that is useful to your person on day one. Not the app of your dreams; the app that works. Everything else goes on a list, and the list is kept.

The test

For each thing the app could do, ask: "If the app did everything else but not this, would my person still use it?"

If yes, it goes on the Later list.
If no, it's a must-have.

A first version has 3 to 5 must-haves. If you end up with 8, run the test again, harder.

Binder's lists

Must-haves:

The user can search a card from free card data, or type it in by hand, and add it as its exact printing with condition and how many copies.
The user can see a list of their cards, each with its value, and the collection's total at the top.
The user can open a card, see every detail in full and how its value has changed, change it, or delete it.
The user can keep a wishlist and see which cards from a set they still need.
The user can add sealed products and graded slabs as their own kinds of item.

Later: scanning cards with the camera, prices from a price service that update themselves, price alerts, deals and buy lists, a show mode, customer records, selling or trading with other people, sharing the collection, backup to the cloud, paying for extras.

In the first version a value comes from the free card data, where it has one, or is a number the user types. Prices from a licensed price service need a server; the guide gets you there after the collection works. A typed value still makes the app useful on day one.

Notice each must-have is one line and starts with "The user can" or "The user gets". That form makes it clear what to build and how to tell when it's done.

Things that are always "Later" in a first version

Accounts and sign-in (Part 8 adds them properly).
Paying for anything (Part 15).
Sharing between people, or anything that needs a server.

Live prices from a price service, and card scanning. Both need paid services and a server, compared in Part 9, and lots of testing. A free card data source that needs no key, plus typed values, works on day one.
A marketplace or messaging between users. That needs reporting, blocking, disputes and sometimes tax rules, and a lawyer for the terms.

These are the parts that take the longest and go wrong most. A first version that saves everything on the phone alone is faster to build and easier to test.

Let Claude sort your list

The message for your kind of app already contains a long wish list. Read it, cross out anything you don't want, add anything missing, then send it.

Collection tracker

Copy for Claude

I'm building a trading card collection tracker, and I'm a beginner. Here is everything I might want it to do, in no order: add a card by typing its name, set and number; search a card from a list; pick a condition; say how many copies I have; what I paid for each card; a value for each card; the total value of the collection; a wishlist; which cards from a set I still need; photos of my own cards; scan a card with the camera; prices that update by themselves; price history charts; sealed boxes and packs; graded slabs with their grade; share my collection with a friend; sort and filter the list; export to a spreadsheet; backup to the cloud; dark mode. Sort this into two lists. MUST HAVE: 3 to 5 things; without each one the app is useless to a collector on day one. LATER: everything else, kept, not deleted. Be strict with me. Write each must-have as one line starting with "The user can". Finally, tell me if any must-have secretly needs an account, a server, an outside price service or payments, because those wait for later. A free card data source that needs no key is fine in the first version.

Seller's app

Copy for Claude

I'm building an app for selling trading cards at card shows and in deals, and I'm a beginner. Here is everything I might want it to do, in no order: my stock with what I paid and my asking price; add a card by typing its name, set, number and condition; a quick buy at the table with the market price, my buy percentage, and a cash or trade rate; a deal screen that adds up several cards; a customer view that shows prices and the offer but hides my costs and profit; sales and totals for each show; starting cash and table fees; receipts with my business name; price labels; a "we're buying" list; scan a card with the camera; prices that update by themselves; helpers at the table with their own sign-in; taking card payments; a public page customers can open; export for taxes. Sort this into two lists. MUST HAVE: 3 to 5 things; without each one the app is useless to a seller at their next show. LATER: everything else, kept, not deleted. Be strict with me. Write each must-have as one line starting with "The user can". Finally, tell me if any must-have secretly needs an account, a server, an outside price service or payments, because those wait for later. A free card data source that needs no key is fine in the first version.

Shop app

Copy for Claude

I'm building an app for a trading card shop, and I'm a beginner. Here is everything I might want it to do, in no order: our stock of single cards with set, number, condition, quantity and price; sealed products with quantity and price; add stock by typing; a public storefront page customers open on their phones; customers' want lists, and a notice when a wanted card comes in; a buy list of what we're looking for; staff sign-ins; sales reports; price labels; scan a card with the camera; prices that update by themselves; online orders; loyalty points; an events calendar; export for the accountant. Sort this into two lists. MUST HAVE: 3 to 5 things; without each one the app is useless behind the counter on day one. LATER: everything else, kept, not deleted. Be strict with me. Write each must-have as one line starting with "The user can". Finally, tell me if any must-have secretly needs an account, a server, an outside price service or payments, because those wait for later. A free card data source that needs no key is fine in the first version.

Argue with the result if you disagree, then copy both lists into your notes under "Must-haves" and "Later".