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Case study · retail and loyalty

A loyalty app for the Świat Książki bookstore chain.

One mobile channel connected loyalty, shopping, promotions, and product availability across a nationwide bookstore network.

Talk about a similar projectSee the product
Home screen and coupons in the Mój Świat Książki app
100,000+
app downloads
Top 1
on the App Store in 24 hours
On time
despite scope changes

Client scale

An app for a retail network present in 130+ locations across Poland

Świat Książki combines a nationwide bookstore network with an e-commerce catalog of more than one million products. The mobile product had to connect loyalty, catalog, and the purchasing experience of a brand operating both online and across many physical locations.

Official Świat Książki website
Interior of a Świat Książki bookstore
130+
locations across Poland

A nationwide physical retail network.

1m+
products online

Books, e-books, audiobooks, and a broad additional range.

Online + offline
one commerce ecosystem

E-commerce, bookstore pickup, and loyalty.

01

A consistent loyalty program across the app and bookstores.

02

Integration with established sales systems and customer data.

03

Catalog, promotions, and coupons configurable for a large network.

04

Stability under high daily user activity.

Starting point

Challenge

The chain needed mobile-first loyalty: a digital identifier instead of plastic cards, consistent promo communication, and a catalog tied to the points program.

On the technical side the hardest work was integrating with long-running store systems without breaking data integrity or slowing product iteration.

Business 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.

Solution

Four layers of one customer experience

01

Loyalty engine

Points, a digital card, coupons, and offers work as one understandable flow.

02

A home screen controlled by the business

Marketing can arrange sections, banners, and campaigns without waiting for every new release.

03

Legacy-system integration

The integration layer preserves continuity across customer, transaction, and loyalty data.

04

Reliability at scale

The architecture supports high daily activity and continued development on iOS and Android.

The product in practice

The shipped interface is the strongest proof

Four selected views show the journey from inspiration to loyalty and a visit to a bookstore.

01

Home screen with offers and recommendations

Stories, promotions, and book carousels in one place.

02

Digital loyalty card

Customer identifier always available during a bookstore visit.

03

Book catalog and availability

Searchable titles and product information inside the app.

04

iOS and Android experience

React Native kept the experience consistent across platforms.

Project delivery

Delivered on time — despite scope changes

DDT, fast business decisions, and close collaboration between development and QA kept the launch on schedule.

roughly 10% additional work and 15% change to initial assumptions

Despite roughly 10% additional work and about 15% change to initial assumptions, the app shipped in the originally agreed timeline.

  1. 01Discovery and DDTWe ran our DDT process (Discovery, Design & Technology) so integrations and risks were mapped before heavy engineering started.
  2. 02UX/UI designPrototypes, information architecture, and a consistent interface system.
  3. 03Development and integrationsAn integration layer connects the React Native app to existing backends so transaction and points data flow safely and consistently.
  4. 04Testing and UATA big win was tight dev and QA collaboration. With crisp user stories we caught issues well before the release train.
  5. 05LaunchWe ran retrospectives after stages-which surfaced risks early (for example longer App Store review) without pushing pressure to the launch date.
Client testimonial

We are pleased to recommend GMI Software, with whom we work on the creation and continued development of the mobile app for the Świat Książki bookstore chain's loyalty program.

GMI Software was responsible for developing the Android and iOS applications, the supporting technology backend, and integrations with our systems. The app allows customers to use a digital loyalty card, collect points, activate coupons, and check promotions available in our physical bookstores.

From the start of our collaboration, we have been able to count on strong commitment, efficient communication, and openness to our ideas. The team understands our needs well and responds quickly to questions and challenges as they arise. We also value their flexible approach and willingness to work together to find the best solutions.

GMI Software continues to support us in maintaining and developing the app. We can recommend the company as a reliable and committed technology partner for building and developing mobile applications.

Grzegorz Biedak
Operations Director, Księgarnie Świat Książki bookstore chain
Translated from Polish.

See the result

Video case study and the live app

Selected shots from the shipped product. Click a thumbnail to open a larger view.

App StoreGoogle Play

Technology

One codebase. A consistent experience on iOS and Android.

React NativeiOS and AndroidLegacy APIs and integrationsLoyalty programConfigurable content
Technology: React Native

FAQ

Frequently asked questions

Answers about scale, integrations, timing, and continued product development.

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.

Facing a similar challenge?

Let us design an app that connects sales, loyalty, and data.

In a short consultation, we will cover risks, integrations, and the safest route to a working product.

Book a consultationSee other case studies
Related capabilities

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From strategy and architecture to app development, release, and maintenance.

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  • React Native

    Expo stack, comparisons and technology expertise.

From client proof to your use case

See how this experience transfers to other scenarios

Subscription app for bookstores and publishers

Subscriptions + recommendations + release notifications

Loyalty app for retail chain

Coupons, personalization and push that drive returns

Contact

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.

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