Build a Shopify app and earn monthly from the App Store
Millions of shops run on Shopify, each with small problems that cost them sales, and Shopify keeps 0% of your first $1M in lifetime app revenue. Start with a free script that audits a real store's catalogue in ten minutes, and sell that audit while you build. Finding a problem merchants will pay to fix is most of the work, so this mission puts it first.
- Working core code for an example app: the audit logic, plan gating, webhook HMAC check and compliance handler, a GraphQL query validated against the 2026-10 schema, and 19 passing tests
- Money in month one: the same audit sold as a £49 one-off service while the app is being built
- The launch paperwork and the maths: App Store checklist, listing and support templates, a 2-year revenue model with your real hourly rate, a weekly routine and a first 30 days
- Comfort with JavaScript or TypeScript and reading API docs. If you've never built a web app, do Build your own API in Python with FastAPI and Use Git without memorising commands first
- Node.js 22.18 or newer for the kit (Shopify CLI needs 22.12 or newer and Git 2.28 or newer)
- Later, your own free Shopify Partner account (you create it yourself, in step 5). Nothing before that needs an account
- The kit: download it all as a zip, or read the kit overview and grab just the example app code
- About 4 hours for the mission, then around 10 hours a week for two or three months before launch
Spot the gap, and plan your start
Know how the money works, what Shopify takes, what you're up against and what it takes in hours.
Shopify's 2025 annual report says it had millions of merchants in more than 175 countries at the end of 2025, 31% of them in Europe, the Middle East and Africa, and more than 21,000 apps in the App Store (Form 10-K ↗). In April 2025 Shopify said it had paid out more than $1B to developers ↗ the previous year. Most of that goes to big apps. But the model works at small scale too, because merchants pay monthly for small tools that save them time or stop them losing sales.
How the money worksA merchant installs your app from the App Store and picks a plan. Shopify adds your charge to their Shopify bill, collects it and pays you. You never handle a card. Here's what it costs you:
- Joining the Partner Program: free (Shopify Help Center ↗).
- Revenue share: you keep 100% of your first $1,000,000 of lifetime gross app revenue counted from 1 January 2025, and 85% above that. To get it you register once for $19 per Partner account (revenue share ↗). It's on gross revenue (refunds aren't deducted), and linked developer accounts count together toward the $1M.
- Processing fee: 2.9% on all app billing, plus any sales tax. This applies even while your revenue share is 0%.
- Payouts: twice a month once your balance is over $25, in US dollars, through Hyperwallet (getting paid ↗).
- Hosting: your app runs on your own server. Example: Render ↗ lists a web service from $7 a month and Postgres from $6.
What a good small app looks likeOne job, done well, for a specific kind of shop. "Flags products that ship with no weight before your shipping rates go wrong" beats "AI-powered store optimisation suite". Small and boring is fine. Small and boring with a clear outcome is what merchants pay $5 to $20 a month for.
Tip- What it takes. It's a product: income starts once the app exists, passes App Store review and gets found, which is why step 8 shows you how to sell the audit as a service in the meantime.
- Discovery is the real work: with 21,000+ apps, a new listing needs merchants sent to it, and step 7 covers where the first 100 installs come from.
- Timeline: plan for 2 to 3 months of evenings to launch a first app, then steady months of support and small improvements as income builds.
- Churn: shops close or switch every month, so good onboarding and support are what keep the numbers climbing.
- Responsibility: you hold access to real businesses' data, so you keep it safe and delete it when asked.
- Who this suits: you can already code, you're building for income over months rather than this month, and you're happy answering merchant support emails. Keep your day job while it grows. Everything before launch is free.
Your first win: audit a real catalogue nowMost Shopify stores publish their products at
/products.json. The kit's quickcheck.py reads it, 250 products a page, and lists products with no images, shipped items with no weight and compare-at prices that don't show a sale. Run it on your own store, or a merchant friend's with their OK (it needs uv, or plain Python):Terminaluv run quickcheck.py their-store.myshopify.comExample of what you'll seeSea Salt Reed Diffuser -> 200ml: ships with no weight; 100ml: compare-at price doesn't show a sale Gift Wrap -> no images ... Checked 212 products. 31 need attention, 14 ship with no weight.Every line is a problem costing that shop money, found without logging in. That's the whole business in miniature: a small, boring check merchants can't easily do themselves. Step 7 turns it into the app's sales funnel, and step 8 shows how to get paid for it as a service while you build.
Next: prove the problem is real before you build. Most people skip that boring part, which is exactly why the next two steps are where you win.