Building a Companion Commerce App for a Hardware Brand

When a hardware brand sells a machine that runs on consumables (capsules, pods, filters, cartridges), the first sale is only the start of the relationship. The business is built on the second, tenth and fiftieth order. A companion commerce app exists for that: to make reordering faster than any alternative, to reward loyal owners, and to tell them about new flavours or products without becoming noise.

I built the commerce app for Bartesian, a capsule cocktail machine brand: a catalogue of 40+ capsules with shop-by-spirit browsing, subscribe-and-save, orders, member pricing, loyalty and push-driven merchandising. This guide covers ecommerce app development for this kind of brand, where the app's audience is people who already own your product: what to build, how subscriptions and loyalty should work, how to merchandise with push without burning trust, and the architecture underneath.

Key takeaways

• The app's job is repeat purchase. Optimise for "reorder in under a minute", not for browsing like a department store.
• Physical goods use normal payments, such as Apple Pay, Google Pay and cards, not in-app purchase.
• Subscribe-and-save needs self-service: skip, swap, pause and change frequency without contacting support.
• Member pricing and loyalty reward owners for buying direct rather than from a marketplace.
• Push is a merchandising channel when it's relevant and rare: launches, restocks and replenishment reminders.
• Headless commerce lets the app share products, inventory and orders with the brand's website.

Why a companion app, when there's already a website?

The website wins new customers. The app serves existing ones, and they behave differently: they know what they like, they buy the same products repeatedly, and they respond to news about the device they own. An app adds things a mobile website struggles with:

• Saved preferences and one-tap reorder, with Apple Pay or Google Pay at checkout.
• Push notifications for launches, restocks and "running low?" reminders.
• A home for owners: member pricing, loyalty status, recipes and device help in one place.

If your customers buy once a year, an app probably isn't worth it. If they buy every few weeks, it can become the most valuable channel you have.

The features that matter

Payments: physical goods aren't in-app purchases

Apple's guideline 3.1.3(e) says apps that sell physical goods or services consumed outside the app must use purchase methods other than in-app purchase, "such as Apple Pay or traditional credit card entry". Google Play's rules are similar for physical goods. So a commerce app uses your payment provider directly, which also means no store commission on capsule orders. Offer Apple Pay and Google Pay prominently: for repeat customers, a wallet payment is the fastest checkout there is.

Subscribe-and-save that customers don't cancel

Subscriptions for consumables live or die on flexibility. Customers cancel when they're stuck with too much stock, the wrong flavours or a delivery while they're away. Give them control:

• Skip or delay the next delivery in one tap.
• Swap products inside the subscription without cancelling it.
• Change frequency as their usage changes.
• Pause for holidays, with an automatic restart date.
• Remind before charging, with a preview of what's coming and a link to edit it.
• Handle failed payments with retries and a simple way to update the card, before the subscription lapses.

Each of these turns a would-be cancellation into an edit, and saves a support ticket.

Member pricing and loyalty

Owners of your hardware are your best customers, and a direct relationship is worth paying for. Member pricing (a lower price for registered owners or subscribers) and loyalty (points, tiers or free products after a number of orders) both give people a reason to buy from your app rather than a marketplace. Keep the rules simple enough to explain on one screen, show progress towards the next reward, and calculate everything on the server so prices and points can't be manipulated from the app.

From the field: For Bartesian, a capsule cocktail machine brand, I built the commerce app around repeat purchase: a 40+ capsule catalogue with shop-by-spirit browsing, subscribe-and-save, orders, member pricing, loyalty and push-driven merchandising.

Push-driven merchandising without burning trust

Push can sell, and it can get your app's notifications turned off for good. The difference is relevance and restraint:

• Segment by behaviour: people who buy a flavour hear about its restock; subscribers don't need "reorder now" pushes.
• Time replenishment reminders from purchase history (for example, when a typical box would be running out).
• Announce launches to owners first, with a deep link straight to the product.
• Limit frequency and respect quiet hours and time zones.
• Measure revenue per push and opt-out rates together. A campaign that sells today but doubles opt-outs is a loss.

Ask for notification permission after a meaningful moment, such as the first order, with a clear promise of what you'll send.

Architecture: headless commerce plus a native app

Most brands already run a store (Shopify, BigCommerce, Salesforce Commerce or a custom platform). The app should share its products, prices, inventory, customers and orders rather than duplicate them:

• App: React Native for iOS and Android, with a fast, cached catalogue and a persistent cart.
• Commerce backend: the existing platform's APIs (for example, Shopify's Storefront API), or a custom service if the brand's rules don't fit.
• Checkout: native checkout with Apple Pay and Google Pay, or the platform's mobile checkout kit.
• Subscriptions: the platform's subscription features or a dedicated subscription service connected to it.
• Content: a CMS for recipes, launches and banners, so marketing can update the app without a release.
• Notifications: a push service with segmentation and deep links.
• Analytics: conversion, repeat purchase rate, subscription churn and push revenue.

Metrics that tell you it's working

• Repeat purchase rate and time between orders for app users versus web.
• Subscription retention, plus skips and swaps (healthy) versus cancellations (not).
• Checkout conversion and wallet payment share.
• Push opt-in rate, revenue per campaign and opt-outs.
• Average order value and loyalty redemption.

Ecommerce app development cost

Two decisions set most of the price. The first is whether the app sits on an existing commerce platform (Shopify, BigCommerce, Salesforce Commerce) or a custom backend: reusing a platform's products, checkout and orders removes hundreds of hours. The second is how much beyond browsing and checkout you need: subscriptions, loyalty, member pricing, multiple currencies and push campaigns each add real work. The planning ranges below show how those choices play out.

Subscriptions on Shopify

If the store runs on Shopify, subscriptions come from a subscription app built on Shopify's subscription APIs: Shopify's own Subscriptions app, or third-party apps such as Recharge, Skio or Loop. The mobile app then reads and manages each customer's subscription (skip, swap, pause, change frequency) through that app's API or Shopify's customer account APIs, so the website and the app always show the same subscription.

Examples of ecommerce apps built with React Native

Shopify builds its own mobile apps, including the Shop app, with React Native, and created FlashList, a widely used React Native list component, while doing so. That's a useful signal that React Native handles large catalogues, fast lists and frequent releases in commerce at scale.

Selling in India and the Gulf

Payment methods differ more than catalogues do. In India, UPI is central and Razorpay is a common gateway; in Kuwait, KNET; in Saudi Arabia, mada cards alongside Apple Pay. Cash on delivery is still common in both regions, so plan for it in order flows. For Gulf markets, design for Arabic and right-to-left layouts from the start rather than retrofitting them.

What it costs to build

As planning ranges: a companion commerce app on top of an existing headless platform, with catalogue, checkout, subscriptions, orders, loyalty and push, typically takes 600 to 1,000 hours. A custom commerce backend, complex member pricing or several markets with different currencies and taxes push that to 1,200 to 2,000+ hours.

FAQ

What is a companion commerce app?

It's a mobile app for people who already own a brand's product, focused on buying consumables and accessories, managing subscriptions, earning loyalty rewards and hearing about launches. Its main goal is repeat purchase rather than new customer acquisition.

Do ecommerce apps have to use Apple's in-app purchase?

No, not for physical goods. Apple's guideline 3.1.3(e) requires apps selling physical goods or services used outside the app to use other payment methods, such as Apple Pay or card entry. In-app purchase is for digital content and features.

How do subscribe-and-save programs reduce churn?

By giving customers control. Letting them skip, swap, pause and change frequency in one tap turns many would-be cancellations into edits. Reminders before each charge and smooth recovery from failed payments prevent accidental lapses.

Should a brand build a native app or rely on its mobile website?

If customers buy frequently, an app usually earns its place: faster reorders with wallet payments, push notifications for launches and restocks, and a home for member pricing and loyalty. If purchases are rare, a strong mobile website is often enough.

Next steps

If you sell hardware with consumables and want a commerce app built around repeat purchase, I've built one with subscriptions, member pricing, loyalty and push merchandising. Get in touch, or see my work.

Sources

• App Review Guidelines (3.1.3(e)), Apple
• Storefront API, Shopify
• Apple Pay, Apple
• Google Pay API, Google
• Notifications, Expo documentation
• Subscriptions on Shopify, Shopify
• FlashList, Shopify