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Shopify App Development

Shopify app development is building software that adds features to Shopify through its APIs, app extensions and Functions. Ecomzier builds public apps for the Shopify App Store and custom apps for a single store or Shopify Plus organization, from checkout logic and admin tools to ERP, marketplace and TikTok Shop integrations.

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1,100+ Shopify stores built, 11 eCommerce awards and 400+ five star reviews.

What is Shopify app development?

A Shopify app is a separate web application that talks to a store through the GraphQL Admin API and plugs into Shopify where merchants and buyers already work: the admin, the online store theme, checkout and point of sale. Apps are built with Shopify CLI and managed in the Dev Dashboard, and business logic that must run inside Shopify, such as custom discounts or checkout validation, is written as Shopify Functions.

The first decision in any Shopify app development project is distribution. A public app can be installed by many stores and needs Shopify approval to be listed in the App Store. A custom app is installed on one store, or on several stores in the same Plus organization, and is never listed (Shopify developer docs). That one choice decides how you bill, which review you go through and which features are available, so we settle it before any code is written.

Shopify apps we build

Every project lands in one or more of these six categories. Each card links to the page that covers it in depth.

Public apps for the App Store

Apps you sell to many merchants: embedded admin interface, Billing API pricing, theme app extensions and a listing that is ready for Shopify review. Shopify public app development.

Custom apps (formerly private apps)

Apps made for one store or one Plus organization, created in the Dev Dashboard and installed with a link. Shopify private app development.

Store specific features

Configurators, bundles, wholesale rules, loyalty logic and admin tools designed around your own operations. Custom Shopify app development.

System integrations

Two way sync of products, inventory, orders and customers between Shopify and your ERP, PIM, OMS, WMS or 3PL. Shopify app integration.

Checkout and Shopify Functions

Discount, delivery, payment, cart transform and validation logic as Functions, plus checkout UI extensions. Customizing the information, shipping and payment steps needs Shopify Plus (Shopify Help Center).

Marketplace and sales channel connectors

Apps that list products and sync orders and stock with marketplaces. This is the kind of app we publish ourselves: see our Shopify apps.

Public app or custom app: which one do you need?

The technology is the same. The rules are not. This table summarizes the differences documented by Shopify (distribution, Functions, protected customer data).

QuestionPublic appCustom app
Who can install it?Any Shopify store, through the App Store listing.One store, or several stores in the same Shopify Plus organization, through an install link you generate.
Listed in the Shopify App Store?Yes, after Shopify approval.No.
Shopify reviewRequired. The app must meet the App Store requirements.No App Store review.
Charging merchantsThrough the Shopify Billing API or Shopify App Pricing only.Cannot charge through Shopify app billing. You invoice directly, if at all.
Shopify FunctionsWork on stores on any plan.Only stores on Shopify Plus can use custom apps that contain Functions.
Protected customer dataAccess to name, email, phone and address is requested and reviewed.Access is always available to the store that installs it.
Best forA product you want to sell to many merchants.Your own store, brand group or a client specific workflow.

Proof that we ship Shopify apps, not just client code

Ecomzier builds and runs its own public apps. Our EZ TikTok Shop Connector is listed in the Shopify App Store and carries the Built for Shopify badge, which Shopify reserves for apps that meet its highest standards for performance, design and integration (Built for Shopify requirements). Our Ecomzier Amazon Connector imports Amazon products into Shopify and keeps inventory and orders in sync. Both are on our Shopify apps page.

That matters for client projects. We deal with App Store review, Billing API plans, webhooks, rate limits, API version upgrades and merchant support on our own products every month, so the same habits go into the apps we build for you.

How we run a Shopify app development project

Six steps for public and custom apps alike. Scope and distribution are fixed before development starts.

  1. Step 01

    Discovery

    We map the problem, the users, the data the app needs and which Shopify surfaces it must appear in.

  2. Step 02

    Architecture

    Distribution, API scopes, webhooks, Functions and extensions are chosen and written into a technical plan.

  3. Step 03

    Design

    Admin screens follow Shopify design patterns so merchants know how to use the app on day one.

  4. Step 04

    Build

    We develop with Shopify CLI against development stores, with code review on every change.

  5. Step 05

    Test and launch

    Real orders, edge cases and load are tested. Public apps go to review; custom apps get an install link.

  6. Step 06

    Maintain

    Shopify ships a new API version every three months and supports each for at least 12 months (Shopify), so we keep apps current.

Shopify app development FAQ

What does a Shopify app development company do?

It plans, designs, builds, tests and maintains apps that extend Shopify. At Ecomzier that covers public App Store apps, custom apps for one store or Plus organization, Shopify Functions, checkout, admin and theme app extensions, and integrations with ERP, PIM, OMS and marketplace systems.

What is the difference between a public app and a custom app?

A public app can be installed by many stores, is listed in the Shopify App Store after Shopify approval and must bill through Shopify. A custom app is installed on one store or on stores in one Plus organization, is not listed and cannot use Shopify app billing (Shopify developer docs).

Do I need Shopify Plus to use a custom app?

No. Any store can install a custom app. Shopify Plus is needed when the custom app contains Shopify Functions (Shopify developer docs) and when it customizes the information, shipping or payment steps of checkout (Shopify Help Center).

Can Shopify still create private apps?

No. Private apps were deprecated in January 2022 and were converted to custom apps automatically (Shopify developer docs). Today a single store app is a custom app created in the Dev Dashboard. Our private app development page explains the change.

How much does Shopify app development cost?

It depends on scope: the number of screens, integrations, Functions and extensions, the data volume and whether the app must pass App Store review. We do not publish fixed prices. After a discovery call you receive a written scope and a quote for that scope.

Which technology do you use to build Shopify apps?

Shopify CLI and Shopify app templates, the GraphQL Admin API, App Bridge for embedded admin interfaces, Shopify Functions for backend logic and app extensions for checkout, admin and themes. New public apps must use the GraphQL Admin API only (App Store requirements).

Do you maintain Shopify apps after launch?

Yes. Shopify releases a new API version every three months and supports each stable version for a minimum of 12 months (Shopify developer docs). Maintenance keeps your app on a supported version, fixes issues and adds features as your needs change.

Can you connect Shopify to our ERP or marketplace accounts?

Yes. Integrations are one of the most common app projects we deliver, either as a custom app or by configuring an existing connector. See Shopify app integration for system integrations and our Shopify apps for marketplace connectors.

Talk to a Shopify app developer

Ecomzier has built 1,100+ Shopify stores that have generated $500M+ in client revenue, backed by 11 eCommerce awards and 400+ five star reviews. Tell us what your app needs to do and we will recommend public or custom distribution, the Shopify features to use and a realistic scope.
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