Retail and loyalty
How GMI Software built a modern loyalty app for the Świat Książki bookstore chain
We delivered a mobile MVP for one of the largest Polish bookstore chains. Fixed-price delivery, React Native, and integrations with legacy systems. Built for high traffic volumes, it shipped on schedule despite roughly 10% scope expansion and changes to about 15% of tasks during delivery.
- Industry
- Bookstore chain and e-commerce
- Product
- Mój Świat Książki
Business context
The chain needed mobile-first loyalty: a digital identifier instead of plastic cards, consistent promo communication, and a catalog tied to the points program.
The critical part was connecting a new client with existing infrastructure (legacy sales systems) and purchase motivation - including near-real-time point accrual.
Project goals
- Digitize loyalty: move from plastic cards to a digital identifier (barcode).
- Let marketing configure the home experience: sections, stories, and campaigns.
- Scale reliably for high daily active usage.
- Integrate legacy systems while keeping data continuity.
Challenge
On the product side we combined lightweight SMS onboarding, a clear home experience, and a points journey from product selection through in-store scanning to visible balances.
On the technical side the hardest work was integrating with long-running store systems without breaking data integrity or slowing product iteration.
The GMI Software approach
We ran our DDT process (Discovery, Design & Technology) so integrations and risks were mapped before heavy engineering started.
1. A loyalty engine tailored to the brand
Instead of an off-the-shelf box, we shipped a custom points engine: advanced near-real-time rules and a path from product to in-store scan that stays coherent.
The program stays understandable on first launch: how to earn points, redeem coupons, and where app-only offers live.
2. A home experience driven from an admin panel
The Świat Książki team can arrange the home screen-order of stories, banners, carousels, campaigns, and targeted coupons-often without a new store release.
The app UI follows familiar e-commerce patterns: search, carousels, clear promo badges, and navigation to home, catalog, card, and profile.
3. Legacy integration
An integration layer connects the React Native app to existing backends so transaction and points data flow safely and consistently.
“We are not afraid of legacy. Integration moved quickly and kept continuity between older databases and the new app.”
Mój Świat Książki app screens
Selected shots from the shipped product. Click a thumbnail to open a larger view.
Stories, promotions, and book carousels in one place.
Quick access to profile data, consents, and preferences.
Customer identifier always available during a bookstore visit.
Offers connected with points, rewards, and purchases.
Users move from inspiration to a concrete loyalty benefit.
Searchable titles and product information inside the app.
Promotions, points, and navigation support purchase intent.
One interface language for catalog, promotions, and account.
The app connects loyalty, offers, and customer communication.
React Native kept the experience consistent across platforms.
See the final result
Try the app yourself:
Why delivery kept its pace
We ran retrospectives after stages-which surfaced risks early (for example longer App Store review) without pushing pressure to the launch date.
On the client side fast business decisions and a dedicated project coordinator kept developer flow steady.
Despite roughly 10% additional work and about 15% change to initial assumptions, the app shipped in the originally agreed timeline.
Voices from the GMI Software team
“I am proudest of the points system: dynamic rules and near-real-time accrual that really nudges purchases. Keeping stability under high daily activity was demanding-and we delivered.”
“A big win was tight dev and QA collaboration. With crisp user stories we caught issues well before the release train.”
Why React Native?
Świat Książki chose cross-platform: one codebase for iOS and Android, faster UI iteration, and consistent UX on both platforms.
- One codebase instead of two separate native apps.
- Faster cycles to test and ship UI changes.
- Consistent UX regardless of the user phone OS.
Key product capabilities
- Earn points on purchases and redeem discount coupons
- Promotions dedicated to app users
- Book availability and searchable catalog
- Phone number and SMS code login
- Configurable home screen (sections, banners, campaigns)
- Loyalty card and user profile
Stack and integrations
React Native with one codebase for iOS and Android, plus backend services for auth, catalog, and loyalty. DDT before build reduced legacy integration risk.
Download the app
Available on Google Play and the App Store.
Frequently asked questions
Does the Świat Książki app support mobile payments?
The MVP focuses on the loyalty program, offer presentation, and personalized coupons. Integration with sales systems lets users collect points for in-store and online purchases.
How did GMI Software handle Świat Książki legacy systems?
The DDT phase mapped system touchpoints precisely. The team built an integration layer so the modern app can talk to older databases safely and efficiently.
How long did it take to build the Świat Książki app?
The project stayed on schedule despite evolving requirements (roughly 15% of tasks changed during delivery).
Is the app scalable?
Yes. The architecture supports high daily traffic and loyalty-point operations at scale.
What sets GMI Software process apart for rollouts like this?
Rigorous retrospectives and structured client communication matter most. Fixed-price assurance after DDT and QA in every sprint reduce budget and timeline drift.
Summary
Mój Świat Książki is an MVP that combines loyalty, offers, and catalog in one mobile channel-built for scale, legacy IT integration, and a predictable partnership model (fixed price after DDT). Need a loyalty app or legacy integration partner? Book a consultation-we can help plan DDT and next steps.
Get in touch with us
Let's talk about how we can implement a solution for your project.
Related GMI services
See how we build similar products for international clients.
Let's talk
about the project.
Have an app idea or need technological support? Write to us — we'll prepare a preliminary analysis and estimate within 48h. Projects that go through our DDT process (Discovery, Design & Technology) come with a price guarantee and a fixed-price agreement — a key differentiator for us.
80-890 Gdansk, Poland