Shopify apps,built and shipped —public or private.
Shopify app development for two kinds of builder: brands that need a custom app for their own store, and SaaS founders launching on the Shopify App Store. We've shipped apps through Shopify's public review process — not just built private apps — and we'll help you figure out which one you actually need before you spend.
By Manpreet Singh, Founder · Proscube
Two kinds of Shopify app — and two kinds of buyer
"Shopify app development" means two very different things, and most of the confusion in this market comes from people not naming which one they're talking about. Before anything else, figure out which builder you are.
The first is a brand founder or operator who needs a custom app for their own store. Something your theme and the off-the-shelf apps can't do — a custom feature for customers, an internal tool for your team, an integration between Shopify and a system you run, an admin extension that automates a workflow. You're not trying to sell software; you're trying to make your own store do something specific. That's usually a private (custom) app, built for one store and never submitted to the App Store.
The second is a SaaS founder who wants to launch a product on the Shopify App Store. You have an idea for an app that thousands of merchants would install, and you want it built, submitted, approved, and live — with billing, onboarding, and a review process to pass. That's a public app, and it's a materially harder build than a private one, because Shopify's review process, performance requirements, and billing API are all part of the job.
Both are real work we do. But they have different costs, timelines, and risks — so the rest of this page is organized around helping you place yourself in the right one.
Public app vs private app — which do you need?
This is the question every prospective Shopify app buyer asks, and getting it right saves you a lot of money. Here's the honest breakdown.
Build a private (custom) app if:
- The app is for your store, or a handful of stores you control. Private apps are installed directly, not listed publicly.
- You need an internal tool, a custom storefront feature, an admin automation, or an integration with your own systems.
- You don't need Shopify's billing API, public listing, or review process — which means a faster, cheaper build.
- You want full control and no obligation to support outside merchants.
Build a public app if:
- You want to sell software to other merchants and be discoverable in the Shopify App Store.
- You're building a product, not a feature — with onboarding, billing, support, and a roadmap.
- You're prepared for Shopify's App Store review, performance and security requirements, and the ongoing work of maintaining a product real merchants depend on.
The short version: if the app serves your business, it's almost always private. If the app is your business, it's public. Most brand founders who think they need a public app actually need a private one — and we'll tell you that on the scoping call rather than selling you the bigger build.
What a Shopify app build includes
Scope depends on whether the app is private or public, but a build with us typically covers:
Scoping & technical design
We pin down what the app does, which Shopify APIs it needs, and — first — whether it should be an app at all or a simpler fix.
App development
The build itself on current Shopify APIs (Admin, Storefront, Functions) — private app for your store, or a public app architected for many merchants.
Admin & checkout extensions
Embedded admin UI with Polaris and App Bridge, plus checkout UI extensions on Plus where the app touches checkout.
Integrations & webhooks
Connections to your systems or third-party services, with webhooks and background jobs for anything that runs on Shopify events.
App Store submission (public)
For public apps: meeting Shopify’s review requirements, listing assets, billing API, and shepherding the app through approval.
Billing & onboarding (public)
For public apps: subscription billing through Shopify’s billing API, plus the onboarding flow that turns an install into an active user.
Performance & security review
Performance budgets and security practices that public apps must meet — and private apps benefit from — built in, not bolted on.
Maintenance & support
Post-launch care: Shopify API version updates, bug fixes, and feature work, via a retainer for apps that need ongoing development.
Why shipping through Shopify's review actually matters
Here's the honest differentiator. Most agencies that list "Shopify app development" have built private apps for a single client's store. That's real work — but it's the easier half of this discipline. The harder half is shipping a public app through Shopify's App Store review process: meeting their performance and security bars, implementing the billing API correctly, passing review (which apps routinely fail the first time), and maintaining a product that real merchants install and depend on.
We've done it: 60K+ aggregate installs across our published Shopify App Store apps. Very few Shopify development agencies have run the public review gauntlet and maintained apps with real install bases — and that experience changes how we build even private apps. We architect to Shopify's standards by default, we know which patterns get apps rejected, and we know what it takes to keep an app alive through Shopify's API version deprecations.
So when we scope your app, the advice comes from having been through the full process — not from having read the docs. If a public app is the right call, we know what approval really takes. If it isn't, we'll say so before you fund a build the market doesn't need.
How an app build runs
Scope & design
We define what the app does, the APIs it needs, and whether private or public is right — then produce a technical design and fixed scope.
Build
Development in sprints with working demos. Private apps are faster; public apps carry billing, onboarding, and multi-merchant architecture.
Submit or deploy
Private apps deploy to your store. Public apps go through App Store submission — listing, billing, and Shopify’s review, which we manage.
Launch & maintain
Live support, Shopify API version updates, and feature work — via a maintenance retainer for apps that keep evolving.
What a Shopify app costs
App cost depends almost entirely on private versus public, and on complexity within each. Private apps for a single store start around $8,000 for a focused tool or feature, and rise with integrations and custom UI. Public App Store apps — with the billing API, onboarding, multi-merchant architecture, and the submission process — run $25,000 to $80,000, depending on scope and how much product surface there is. Complex products with large feature sets or sustained submission cycles can run beyond that, into six figures. Maintenance is separate: most apps, especially public ones, need an ongoing retainer for Shopify API updates and feature work, which we size to the app.
What moves the number:
- Private vs public: the review process, billing, and multi-merchant design make public apps a different order of work.
- Integrations: each external system or Shopify surface the app touches adds scope.
- UI surface: an embedded admin app with rich UI is more than a background automation.
- Ongoing development: a one-off internal tool is different from a product you'll keep shipping to.
What's not included: Shopify’s own fees and any third-party services the app relies on. We scope fixed after the scoping call, and for public apps we'll be candid about the post-launch commitment before you start.
Ready to talk?
Tell us what you want the app to do — internal tool, store feature, or App Store product — and we'll scope it honestly, including whether it should be an app at all.
Reply within 1 business day. Real read, not a sales call.
Who this is for
On the brand side, this is for founders and operators whose store needs something the theme and existing apps can't do — a custom feature, an internal tool, an admin automation, or an integration with systems you already run. On the SaaS side, it's for founders with a genuine App Store product in mind who want a team that's actually shipped through Shopify's review, not one learning on your budget.
Who it's not for:
- Brands that haven't checked the App Store first. Often the feature you want already exists as a well-built app for a few dollars a month — and we'll tell you to use that instead of funding a custom build.
- Founders who want a public app because it sounds like a business, with no evidence merchants want it. Validate demand before you build a product.
- Anyone wanting the absolute cheapest build with no maintenance plan. Apps live on Shopify's evolving APIs; an unmaintained app breaks. We build for the long run, not the lowest bid.
It's also for anyone stuck with an app that's been left behind. If your original developer has gone dark, or an existing app — public or private — has fallen out of maintenance and broken on a Shopify API update, that's a job we do regularly: we audit the codebase, get it back onto current APIs, and either stabilize it or rebuild it. App rescue is a real need most agencies won't touch, and it's often faster and cheaper than starting over.
If an app isn't your best move, we'll say so on the scoping call.
Private app vs public app vs off-the-shelf
| Private app (Proscube) | Public app (Proscube) | Off-the-shelf app | Generic dev shop | |
|---|---|---|---|---|
| Best for | Your own store | Selling to merchants | Common needs | Varies |
| App Store listing | No | Yes, we submit | Already listed | Often never shipped |
| Shopify review experience | N/A | Done it before | N/A | Usually none |
| Billing API | Not needed | Built in | Their billing | Hit or miss |
| Control & customization | Full | Full | Limited | Varies |
| Typical cost | From $8K | $25K–$80K | $0–$100/mo | Varies |
Related services
Plan on roughly one to four weeks for review itself once the app is submitted and complete — but that's after the build, and it's rarely a single pass. Apps frequently get sent back for changes on the first submission (performance, billing implementation, listing details, or policy compliance), and each round adds time. Because we've been through the process, we build to Shopify's requirements from the start to minimize rounds — but no honest developer can promise a one-shot approval.
If it's built to Shopify's requirements, yes — eventually, possibly after a revision round or two, which is normal. Review covers performance, security, correct use of the billing API, listing quality, and policy compliance. The apps that fail are usually the ones built without knowing the bar. We build to that bar from day one and manage the back-and-forth with Shopify, which is most of what gets an app through cleanly.
If the app serves your own store, it's almost always private — faster, cheaper, no review process. If the app is the product you're selling to other merchants, it's public, and the App Store review, billing, and maintenance come with it. Most brand founders who ask for a public app actually need a private one. We'll place you in the right category on the scoping call rather than defaulting to the bigger build.
Public apps bill merchants through Shopify's billing API — typically a monthly subscription, sometimes with usage-based charges or a free tier, all handled inside Shopify so merchants pay on their Shopify invoice. We build the billing into the app and help you think through the pricing model, but the pricing strategy itself is yours; we implement and advise, we don't dictate what you charge.
Apps need ongoing care because Shopify's APIs evolve and version-deprecate on a schedule — an unmaintained app eventually breaks. Public apps also need bug fixes and support as merchants use them. We offer maintenance retainers sized to the app: API version updates, fixes, and feature work. We'll be upfront about this commitment before you start, especially for public apps, so it's a planned cost, not a surprise.
Usually, yes. We regularly take over apps — auditing the codebase, getting it onto current Shopify API versions, fixing what's brittle, and building forward. Public apps that have fallen behind on API versions or stalled in review are a common case. We'll assess what's there and tell you honestly whether it's better to continue it or rebuild, rather than assuming one or the other.
Got a project?
Ready to build your Shopify app?
Send us your store URL or your idea. You’ll hear back within one business day — an honest read on whether we’re the right fit. No sales call, no slide deck.