Shopify App Development: Custom & Public Apps

Shopify App Development Services and Developers

Stores that ask for an app usually need one of two things: a private tool built around their own operation, or a product to sell to other merchants. Those are different projects with different budgets, and the first question a good Shopify app development company asks is which one you mean.

App development means building software on Shopify's APIs (the interfaces apps use to read and change store data). That covers embedded admin apps your team opens inside Shopify, automations that react to webhooks (instant notices when an order or product changes), and discount or checkout logic built with Shopify Functions.

It is not installing or configuring existing apps, which is app integration and a much cheaper job. If you only need data moving between Shopify and another system, an integration developer is the better hire. Compare the developers below on apps they have shipped, not on starting price.

Plenty of capable web developers can build software. Fewer know how Shopify apps authenticate, request permissions, bill merchants and pass review.

Ask for an app you can install. Screenshots of an admin screen prove little. A public app they built has a listing and reviews you can read, and a custom app can be demonstrated on a development store. If they have neither, you would be funding their first Shopify app.

Ask which permissions the app will request. Apps ask for access scopes, such as reading orders or writing products. A developer who requests only what the feature needs is thinking about your data; one who asks for everything, just in case, is not.

Get hosting and monitoring in writing. Every app runs on a server someone pays for. Find out the monthly hosting cost, whose account it sits in, and how you'll know when a job fails. An unmonitored app tends to fail quietly, often in the middle of a sale.

Settle ownership before the build starts. For a custom app, the code belongs in your repository and the app should sit under an account you control or can have transferred. For a public app, whoever owns the Partner account behind the listing receives the revenue, so make sure that is you.

Red flags. A public app quote with no time for App Store review or for Shopify's mandatory privacy webhooks (the handlers that deal with customer data requests and deletions). A fixed price for a large app with no discovery phase. No plan for who maintains the app after launch.

A custom app is built for your store and installed privately. A public app is a product: listed on the Shopify App Store, installed by merchants you've never met and billed through Shopify. The second costs more because it is a software business, not a tool.

What changes with a public app:

- App Store review: Shopify checks the app against its requirements before listing it, so plan for at least one round of fixes

- Billing: charges run through Shopify's Billing API, with plans, trials and usage fees that must work on every install

- Multi-tenant hosting: one app serving hundreds of stores, each with its own data, install and uninstall events, and API limits

- Support: merchants write in when the app clashes with their theme, and that cost never stops

A custom app skips all four. It still carries the cost few quotes mention: Shopify releases a new API version every quarter and retires older ones, so every app needs periodic upgrades to keep calling a supported version. Ask for that as a line item — a retainer or a fixed annual upgrade — before you sign.

Most merchants should build custom first. Go public only when other merchants are already asking for the tool and you're ready to run support.

Frequently asked questions about building a Shopify app

Should I hire a Shopify app developer or use an existing app?

Start with the App Store. If an existing app covers the workflow and its fees over three years cost less than a build plus maintenance, use it. Build when the process is part of your advantage, when an app's per-order fees become painful at your volume, or when data needs to stay in systems you control. Apps you rely on can also change pricing or shut down, which your own app won't.

How long does it take to build a Shopify app?

Custom apps typically take 6 to 16 weeks from agreed spec to launch, depending on admin screens, data volume and how many systems the app touches. Public apps take longer, because billing, onboarding flows, listing content and App Store review all sit on the critical path. Discovery should end with a milestone plan, so you can spot slippage in week three rather than week twelve.

Do Shopify Functions need Shopify Plus?

It depends on how they're delivered. Functions, Shopify's way to run custom discount, shipping, payment and cart validation logic, always live inside an app. Public apps that contain Functions work on any Shopify plan; custom apps that contain Functions need Shopify Plus. Functions also replaced Shopify Scripts, which stopped running on 30 June 2026, so any store still depending on Script logic needs it rebuilt.

Can a custom app change our checkout?

Partly, and your plan decides how far. Checkout UI extensions (app-built blocks inside checkout) on the information, shipping and payment steps need Shopify Plus. Extensions on the Thank you and Order status pages are available on all plans. The older route of editing checkout.liquid or adding Additional Scripts to those two pages has now closed on every plan, so any quote built on it is out of date.

Do I need an agency or a freelance Shopify app developer?

In September 2026, the 10 app development specialists on shopexperts were 7 freelancers and 3 agencies. A freelancer suits a single-purpose custom app with a clear spec and a merchant who makes decisions quickly. An agency suits public apps and larger builds that need design, QA, project management and someone to answer support tickets once the app is live. Either way, meet the person who will write the code.

Shopify App Development Services and Developers

Deyan Chernogorski

Rabia Tariq

Let us match you with the right Shopify expert for your needs.

Slash Themes

Dreams To Life, LLC

Tom Hooker

How to choose a Shopify app development agency or freelancer

Shopify custom app development or a public app?

How much do Shopify app developers charge?

$12,000 – $60,000

$30,000 – $120,000+

$100 – $220

What can a custom Shopify app do?

Embedded admin apps

Workflow automation

Discount and checkout logic

Theme app extensions

Public App Store apps

App maintenance

Frequently asked questions about building a Shopify app

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