03 / Product engineering
Mobile apps for Android and iOS from a single codebase, without paying twice
I build customer-facing and internal apps with React Native and Expo, from concept through App Store and Google Play release to further development and maintenance.
A mobile app makes sense when it solves a specific problem: customers should come back more often, a field team should stop working on paper, a process should live in one place instead of phone calls and emails. That question is where I start every project, not the screens. An app nobody opens is just a cost.
I build with React Native and Expo, which means one codebase for both Android and iOS: one quote, one timeline, and one change instead of two for every new feature. I run the project end to end — architecture, backend, testing on real devices, store release and further development. Throughout, you talk to the person writing the code.
That's how IZAPzoo came about — a loyalty app for a retail chain where customers collect points via QR codes and redeem vouchers, while the company runs everything from an admin panel. I also bring the habits gained on systems connected with organizations such as PwC, Roche and E.ON into every project: testing, version control and documentation are my default.
What the service covers
Android and iOS apps from one codebase
Apps built with React Native and Expo run natively on both platforms, and every new feature or fix is written once, not twice. That lowers the build cost and, more importantly, the cost of every change in the years that follow.
Customer apps and loyalty programmemes
Apps that give customers a reason to come back: loyalty programmemes with points and vouchers, QR code systems, bookings and orders. IZAPzoo is one example — a loyalty app for a retail chain with QR codes, points, vouchers and an admin panel to run it all.
- Loyalty programs: points, vouchers, rewards
- QR code systems for earning and redemption
- Push notifications with offers and reminders
- An admin panel for your team
Internal apps for teams
Employee tools that replace paper, spreadsheets and phone-call dictation: field job handling, stocktaking and code scanning, work reports, access to company data from a phone, with permissions matched to roles.
Sign-in, notifications and the app backend
Everything under the hood: secure sign-in, push notifications, offline support, data sync, and the backend and APIs the app runs on. A mobile app is a system, not a set of screens, and I build the whole of it.
- Secure authentication, including biometric sign-in
- Push and in-app notifications
- Offline mode and data synchronization
- Backend, APIs and integrations with existing systems
Store release and maintenance
I take the app through the full App Store and Google Play release process: developer accounts set up in your company's name, store listings, guideline compliance and review. After launch I keep it current with new Android and iOS versions and the stores' evolving requirements.
Typical situations
- 01
Customers do come back, but the loyalty programme is paper stamps that get lost and tell you nothing.
- 02
Your field team writes everything down on paper, and someone retypes it into the system every evening.
- 03
You have an app, but the previous vendor is gone and it keeps breaking with each Android and iOS update.
- 04
Your web product is ready for a mobile version, but a quote for separate Android and iOS builds is beyond the budget.
What you can count on
One codebase for Android and iOS, so every future change costs once, not twice.
An app released on the App Store and Google Play, with accounts and listings owned by your company.
Working builds to try on your own phone during development, not only at the end.
Tested, documented code, with the backend and admin panel included.
Technologies
- React Native
- Expo
- TypeScript
- React
- Node.js
- PostgreSQL
- Supabase
- App Store Connect
- Google Play Console
Questions about this service
For the vast majority of business apps — loyalty, sales, internal tools — React Native with Expo delivers quality indistinguishable from native at a clearly lower cost to build and maintain. There are exceptions, such as advanced 3D graphics or unusual hardware integrations. If your project is one of them, I'll say so plainly in the first conversation.
It depends on scope, which is why I start with a free conversation, after which you get a quote with the scope written out. Larger projects are staged: first a version with the features that actually decide success, then development based on how users respond. The budget stays under control and the app reaches people sooner.
Yes, I run the whole process: developer accounts registered to your company, store descriptions and graphics, compliance with Apple's and Google's guidelines, and the review process itself — including the occasional rejection, which happens in the App Store even to good apps.
Android and iOS change every year and the stores keep tightening their requirements, so an unmaintained app simply stops working over time. I offer ongoing maintenance: monitoring, updates and feature development. If you'd rather hand the project to your own team, the code and documentation are kept in a state that makes the handover realistic.
Related services
Tell me what the app should change in your business
The first conversation is free and non-binding. I'll tell you straight whether a mobile app is the right answer to your problem, and if it is, you'll get a proposed scope, approach and cost range.
- Phone
- +48 573 021 012