Should the app identify coins from the photo?

Not in the first version. Image identification of coins is unreliable across wear and lighting, and a wrong year or mint mark corrupts the collection in a way the user may not notice for months. Fast pickers with remembered defaults get a run of similar coins entered in seconds without that risk. Add recognition later as a suggestion the user confirms, never as an automatic fill.

How should grades be stored?

As a value from a fixed list on the Sheldon scale (for example G-4, VF-20, MS-65) rather than free text, so filters and the want list can compare them. Allow an optional certification field for slabbed coins (service and certificate number) separate from the grade itself.

How to Build a Coin Collection App with AI (2026)

What a coin collection app needs

Coins by country, denomination, year, mint mark, and grade
Front and back photos per coin, plus purchase price, date, and source
Sets (for example state quarters, Lincoln cents by year) with completion percentage
Want list with target grade and max price
Collection value total from purchase prices, with manual current-value override

The screens

Screen	What it does
Collection	Grid or list of coins with filters for country, year range, grade, and set
Coin Detail	Both photos, all attributes, purchase info, notes, and which sets it belongs to
Add Coin	Camera for front and back, then country, denomination, year, mint mark, grade
Sets	Each set with a completion bar; tap in to see owned and missing slots
Want List	Missing coins with target grade and budget, mark as acquired

The data model

Coin: country, denomination, year, mintMark, grade, variety (optional), obverseUri, reverseUri, purchasePrice, purchasedAt, source, currentValue (optional), notes
CoinSet: name, description, slots (array of { year, mintMark, denomination })
SetSlot: setId, slotKey, coinId (optional)
WantItem: country, denomination, year, mintMark, targetGrade, maxPrice, acquiredCoinId (optional)

The build prompt (copy this)

Paste this into ShipNative and it becomes a working React Native app with these screens, navigable in a live preview, in about two minutes:

“A coin collection app for hobbyists. Adding a coin starts with the camera: photograph the obverse, then the reverse, then fill country, denomination, year, mint mark, and grade from pickers with the most recent values preselected so a run of similar coins is fast. Each coin stores purchase price, date, and source, an optional current value, and free-form notes, and can belong to one or more sets. Sets are user-defined lists of slots such as every year and mint mark of a series; the Sets screen shows a completion bar per set and tapping in shows owned slots with their photo and missing slots as outlines. A missing slot can be sent to the Want List with a target grade and a maximum price, and when a matching coin is added the want item is marked acquired. The Collection screen supports grid and list views with filters for country, year range, grade, and set, and the header shows total purchase cost and total current value using the override when present. Photos are stored on device; everything works offline with optional backup. Screens: Collection, Coin Detail, Add Coin, Sets, Want List.”

Then iterate with small, screen-specific prompts (“make the primary button bigger”, “add an empty state”), preview on your own phone, and export the full Expo project whenever you want. The full method: how to build an app with AI.

How it makes money

One-time purchase ($10-15) or a yearly subscription ($8-12) for unlimited coins and cloud backup, with a free tier capped at around 50 coins. Collectors pay for tools that respect their data, so a plain CSV export on every tier is a selling point, not a leak. Do not attempt automatic price lookups unless you have a licensed data source; stale or wrong values are worse than none.

Implementation and the revenue math for every model: how to make money from an app. When you’re ready to ship: App Store and Google Play publishing guides.

Build it now

The prompt above is free to run at shipnative.dev — working coin collection app on your phone today, full code export.

How to Build a Coin Collection App with AI