Checkout extensions and Functions
Pricing rules, delivery options and fields that exist only in your checkout. Shopify Plus.
When no Shopify app fits, we build the one that does.
Some of what your store needs doesn't exist in the App Store: a pricing rule only you use, a link to your ERP. We build a private app for that one job. Fixed price, and the code is yours.
- Scope
- One job, done properly
- Price
- Fixed, agreed up front
- Ownership
- Code in your name
- Timeline
- Typically 6 to 12 weeks
An App Store app is built for thousands of stores at once. You work inside its settings, live with its limits, and pay for it every month. We make one app, for one brand, and hand it over.
When the app you need doesn't exist, the usual answer is a workaround: a spreadsheet, a manual step, a compromise your team makes every day. Every commission starts with your operations instead: your catalogue, your fulfilment, your checkout rules. The result lives inside your Shopify admin, does one job, and has nothing in it you didn't ask for.
Why custom
Off the shelf, or built for you.
Public apps are the right choice for common jobs, and if one already does what you need, we'll say so on the first call. When none of them fits, this is the difference you're paying for.
AspectApp Store appA Moden app
FitBuilt for the typical store. Your team adapts its process to the app's settings.Built around the way your team already works.
RulesThe developer decides what it can do, and what it never will. Feature requests join a queue.Your rules, written into your own code. Changes ship when you need them.
CostA monthly fee for every app, often rising with your plan or order volume.One fixed price for the build. Hosting runs on your own accounts, at cost.
SpeedEach app can load its own scripts and styles on every page, and some leave code in your theme after they're uninstalled.One app that loads only where it's used, tested against your Core Web Vitals before launch.
OwnershipYou rent access. Stop paying and it stops working.Source code in your GitHub organisation. It keeps working whoever maintains it.
DataCustomer and order data passes through another company's servers.Data stays in systems your company owns and controls.
What we build
Any function your store is missing.
These are the commissions we are asked for most. If yours isn't here, tell us about it. Tags show which Shopify plans can run each kind of app.
Integrations and admin tools
Your ERP, warehouse and accounting software talking to Shopify every few minutes. Every plan.
B2B and wholesale
Trade prices, terms and order minimums for stockists, beside your retail store. Every plan.
Storefront features
Configurators, personalisation and product finders, placed by your designers as theme app blocks. Every plan.
Checkout extensions
Custom fields, upsells, delivery notes, gift options and trust content placed directly in the checkout steps.
PlusDiscount and pricing logic
Tiered, bundle, member and conditional discounts written as Shopify Functions, so they run inside Shopify at checkout speed.
Plus for custom appsB2B and wholesale
Trade pricing beyond native catalogue limits, approvals, quick order forms and reorder tools that sit beside your retail store without a second shop.
All plansMemberships and subscriptions
A members' portal, member pricing and subscriptions priced per market, working alongside Shopify's own subscription tools.
Basic and upSystems integrations
Two-way sync with ERP, PIM, 3PL, POS and accounting platforms, with retries, logs and alerts your team can read.
All plansAdmin tools
Internal dashboards, bulk editors, approval flows and reports that open inside your Shopify admin.
All plansStorefront features
Configurators, size advisors, appointment booking and product finders delivered as theme app blocks your designers can place.
All plansAI features
Catalogue writing, customer service, search and forecasting built on your own data, as a feature of your app.
All plans
AI features
AI that knows your catalogue, your customers and your rules.
General-purpose AI tools know nothing about your store. We build AI into your app where it saves your team real time, using the model provider you choose and data that stays in your accounts. AI goes into your app where it helps your customers and staff. It doesn't write your app.
Catalogue assistant. Descriptions, alt text and SEO fields drafted in your brand voice and approved by your team before anything goes live.
Customer service agent. Answers order, delivery and returns questions from live order data and your own policies, and hands over to a person when it should.
Search in your customers' words. Shoppers describe what they're after and see products that match, even when they don't know the product name.
Forecasts and reorders. Sales patterns turned into reorder suggestions and stock alerts before a bestseller runs out.
Back-office paperwork. Supplier emails, invoices and spreadsheets read and turned into Shopify records.
Ready to install
Four apps we have already built.
Each one is finished, tested and installed privately on your store, then set up around how you sell. Need it different? We change it.
Plus and other plans
Built for Shopify Plus. Right for every plan.
Plus gives a custom app the deepest access to checkout and pricing, so that is where most of our work happens. Stores on other plans still get a complete, private app made for them.
For Shopify Plus stores
Shopify Plus
Every checkout step. UI extensions on the information, shipping and payment steps, styled to your brand.
Shopify Functions in a private app. Your own discount, delivery, payment and cart validation rules, not shared with any other store.
More B2B headroom. Unlimited catalogues, direct company assignment and deposits, extended with your trade rules.
Expansion stores. One app installed across your regional stores, configured per market.
For Basic, Shopify and Advanced stores
Every other plan
Admin apps that run your back office from inside Shopify.
Theme app blocks for storefront features without editing theme code.
Integrations with the systems you already pay for.
B2B tools for pricing, approvals and reordering beyond native limits.
Thank-you and order status extensions for post-purchase offers and surveys.
Planning a move to Plus? We design apps so the Plus-only parts switch on when you upgrade, without a rebuild.
How it works
From first call to live store.
A commission follows the same five stages every time. You see a working preview every week from the build stage onward, and the price is fixed once the specification is agreed.
- 01
Discover
Week 1A working session with the people who will use the app. We map the process it replaces, the data it touches and the plan your store is on.
- 02
Specify
1 to 2 weeksA written specification and a clickable prototype inside a development store. You approve the scope and receive a fixed quote.
- 03
Build
3 to 8 weeksWe build in weekly increments. Every change is reviewed by a second developer and tested before it reaches your preview. Each Friday you get a preview link and a short note on what changed.
- 04
Launch
1 weekInstalled on your live store, tested against real orders, and walked through with your team until it feels like it was always there.
- 05
Care
OngoingShopify releases a new API version every quarter. We move your app onto each one before the old version is retired, and keep it monitored.
Who builds it
Every line checked by a second pair of eyes.
Your app is written by the people on your first call. Every change is checked by a second developer and tested before it goes anywhere near your store.
- One team, start to finish.
Nobody hands your project off halfway. The people on the first call are the people who write the code.
- No unchecked AI code.
Code that goes to your store is written by people who can explain every line of it, and reviewed by a second developer before it ships.
- Small on purpose.
Each app does one job, so it stays easy to understand, test and maintain long after launch.
- Tested at every step.
Automated tests, a run-through on a development store with your real catalogue, and a page-speed check before each release.
Turnkey handover
You own the app. We keep it current.
Source code in your GitHub organisation, with a licence that lets any developer continue the work.
Hosting, monitoring and logs set up on accounts in your company's name.
Installed and tested on your live store before we call it finished, including page speed measured before and after launch.
A written handbook and a recorded walkthrough for the people who use it every day.
30 days of adjustments included after launch.
Begin a conversation
Describe the app your store needs.
Plain language is fine. Tell us what should happen, who uses it and what it replaces. We reply with questions, an honest view on whether a custom app is the right answer, or a time for the discovery session.