Enhancing E-commerce Apps for a Leading German Retail Chain

Client Overview
Our client is a renowned German IT solutions provider specializing in mobile commerce technologies. Their software powers a wide range of retail innovations, including mobile payments, Scan & Go, smart vending, self-checkout, and customer analytics — driving operational efficiency and improving the shopper journey for many retailers across Germany.
Project Objectives
The project aimed to elevate the mobile shopping experience for a national retail chain through a comprehensive redesign of its native Android and iOS applications. Our mission:
- Introduce a new backend architecture
- Implement advanced search capabilities
- Improve app UI and navigation
- Ensure regulatory compliance and data privacy
Why GP Solutions?
The client chose GP Solutions for our proven track record in mobile development, excellent communication, and seamless integration into distributed teams. Our specialists rapidly aligned with the client’s agile workflows, demonstrating both technical competence and cross-functional collaboration.
Key Enhancements Delivered

Powerful Search Integration
We engineered an API to connect the client’s newly built website backend with the mobile apps, ensuring data consistency and unlocking real-time search functionality across platforms.

Barcode Scanner & Dynamic Shortcuts
To make product discovery even more effortless, we integrated a barcode scanner accessible via dynamic shortcuts, allowing users to scan items directly from their device’s home screen.
3D Catalog Integration Using a pre-selected third-party library, we built a custom integration between the client’s native app and their 3D product catalog, enhancing visual engagement and driving conversion.
Compliance & Data Privacy Our team implemented critical privacy features, including:
- One-click data deletion in the Android app;
- Full App Tracking Transparency (ATT) support in iOS, ensuring App Store compliance and user trust.
Stability & Performance Optimization

Bug fixing
We conducted extensive refactoring to eliminate legacy bugs and upgraded outdated codebases, delivering a faster, more stable app experience.

UI & Navigation Overhaul
We addressed navigation issues that previously disrupted the shopping journey. Enhancements included:
- Persistent search sessions
- Custom labeling and layout adjustments
- Optimized image formats for improved performance
Business Impact
Thanks to the app overhaul, the retail chain now offers a significantly improved digital shopping experience. Customers enjoy intuitive navigation, fast search, visual product discovery, and trusted data handling.
Android: Java (Android 7-11.0), Kotlin (1.3-1.5.31), FasterXml, STAX, Moshi, AndroidX, OkHttp3, Volley, Ingenico, Firebase, Google Play Services, ZXing, Blaetterkatalog.
IOS: Swift 5-5.5, UIKit, Combine, Firebase, GoogleAppMeasurement, GoogleDataTransport, GoogleUtilities (Network, Logger), FlexibleRowHeightGridLayout, InAppSettingsKit, KeychainAccess, MBProgressHUD, MultiSlider, nanopb, SwiftGen.
Custom mobile app development