Mobile App References – From Idea to App Store
Native iOS/Android, Flutter, React Native (Glossary): See apps we have developed for companies from 10+ industries.
Our Expertise
Mobile Apps for Every Platform
From native iOS and Android apps to cross-platform solutions with Flutter and React Native to enterprise apps – we develop mobile applications that delight users and achieve business goals.
Native iOS (Swift)
Native Android (Kotlin)
Flutter
React Native
IONIC
Cross-Platform
Selected Mobile Apps
Smart Guard Control App
Development of a mobile security application for security guards and security services. The app enables planning and documentation of patrol rounds, event recording, and real-time reporting.
MAM Babyphone App
The MAM Baby Monitor App transforms two smartphones into a full baby monitor system with high-quality audio transmission, noise activation, and visual noise display. Within 4 weeks, the app was installed approximately 40,000 times—full case study with challenge, solution, and results.
Lullio Baby Monitor App
Native app (Swift/Kotlin) with WebRTC live streaming, BLE for offline mode, and on-device ML for sound recognition—two smartphones become a secure baby monitor with HD video, night vision, and two-way audio. Full case study with store links and metrics.
Craftbeer Coin App
Development of a blockchain-based app for craft beer enthusiasts with integrated ERC20 token. The app enables users to manage tokens, redeem them at participating breweries, and find partner locations on an interactive map.
Tankpool24 App
Development of a mobile app for Tankpool24 customers for locating gas stations, price comparison, and cashless payment. The app offers real-time gas station availability, route planning, and a digital payment system for business customers.
Bet Mr. Moo – Quiz App
Gaming and betting app with a luxurious dark UI and gold accents: social quiz rounds, bets on outcomes, and friend invites—full case study covering challenges, solution, and API-first architecture (iOS & Android).
Endurance by Endulytics
Development of a comprehensive fitness tracking app that helps users plan workouts, track progress, and achieve training goals. The app offers personalized training plans, performance analytics, and wearable integration.
dfreeeze Vehicle Control App
Continued development of the dfreeeze vehicle control app: we took over an existing app (not a full greenfield rebuild)—remote control, vehicle status, auxiliary heating; full case study with challenge, solution, and outcomes.
Presentation App
For our client AKHolding, we developed a presentation app (Android tablet + iPad). The app displays a PDF document. On each launch, the app checks if a new version is available on the server and offers it for download. Communication between app and server uses FTP protocol, so API development is not required.
CRV Cattle Breeding App
Development of a specialized app for CRV for managing and analyzing cattle breeding data. The application enables farmers to filter and compare breeding bulls by various parameters such as breed, performance data, and genetic traits to make optimal breeding decisions.
Car Dealership App
For a car dealership, we created an app for vehicle display and customer retention. Vehicle listings are imported from mobile.de or autoscout24.de, avoiding duplicate data maintenance. Displaying vehicle offerings also requires no internet connection. Using QR code scanner, vehicles at the dealership can be found directly in the app and added to a watchlist.
daytime Smart Control SC16 App
Development of an intuitive smart home app for controlling lighting systems. The daytime Smart Control SC16 App enables users to program, save, and control the daily schedule of their lighting. The app features a clear user interface with real-time control and various operating modes.
CRV Repromanager-App
The Repromanager app by our client CRV supports farmers with heat detection and insemination. Sensors capture animal data, which is sent to the app via web services. With just a few clicks, the farmer can also commission an insemination. The app was developed for iOS and Android smartphones and tablets.
InAirQ Air Quality App
Development of an innovative IoT app for monitoring indoor air quality. InAirQ connects to sensors measuring TVOC (volatile organic compounds) and other air quality parameters. The app features an intuitive user interface with real-time readings, trend charts, and notifications when thresholds are exceeded.
Tower Defense Game
Development of a strategic tower defense game with extensive customization options for defense towers. The app features a workshop system where players can equip their towers with special upgrades to develop various combat strategies. The game has an intuitive interface with detailed statistics on damage, fire rate, and range of each tower.
Agri Business Simulation Game
Development of a comprehensive agriculture simulation app that allows players to run their own farm. Agri Business offers various game areas such as field management, animal husbandry, and product processing. The app combines entertaining gameplay with realistic aspects of farming.
Gold Rush 2016 Mobile Game
Development of an entertaining mobile game with a gold prospecting theme. Gold Rush 2016 is an exciting adventure game where players take on the role of a gold digger searching for valuable treasures. The game features a captivating story, lovingly designed characters, and intuitive touch controls.
Mobile POS System for Parking Lots
For our client, we developed a mobile POS system based on Android. The register can verify already issued tickets for validity. New tickets can also be issued and printed along with a receipt via the connected BLE printer. Collected amounts are recorded in the cash book and sent to the backend at end of day.
OTB Cockpit App
For our healthcare client, we created a cockpit app for order entry in medical supply provisioning. The app permanently stores several hundred thousand customer and product records. The app works completely offline and can be synchronized with the server at will. It is currently used daily by several hundred field representatives.
EventConnect - Conference App
Development of a comprehensive conference app for event organizers and attendees. The EventConnect app provides clear access to all important event information: program, speakers, venue, and current news. Attendees can create their personal schedule and set reminders for sessions.
Media Library App
Development of an intuitive media library app for efficient management and organization of digital content. The app enables users to organize their media in various categories, tag them, and search quickly. Offline availability and synchronization with cloud services ensure flexibility and data security.
Vibratissimo App
We received the commission from Amor Gummiwaren GmbH to complete the Vibratissimo apps. Using the Vibratissimo app, a vibrator can be remotely controlled via Bluetooth or the internet. The app includes a complete community with features like chat, messaging system, video chat, and creation of video and image galleries.
Apartment Finder Saxony App
The Apartment Finder Saxony displays the current apartment listings from www.wohnungsfinder-sachsen.de. Unlike other real estate apps, this app can be used offline, e.g. on the train, while traveling, or whenever you have time but no internet connection. The app is available for iOS and Android smartphones.
Yooyuu App
We received the commission from YooYuu GmbH to develop an intelligent app messenger with organizational functions for iOS and Android devices. With the YooYuu app, companies and organizations from various industries can digitally optimize communication and organization - all fully GDPR-compliant.
Tradesperson Planning System
For a roller shutter manufacturer with over 100 employees, we developed a system consisting of backend and Android app. In the backend, orders can be distributed to individual tradespeople. Via the Android app, measurements can be recorded, current orders viewed, and status updated.
EAS App
We received the commission from the Evangelische Arbeitsgemeinschaft for Soldatenbetreuung e.V. to further develop the Flutter-based hybrid app and adapt it to current iOS and Android versions.
dguard Motorcycle Safety App
Takeover and continued development of the dguard motorcycle safety app by Groenewold IT Solutions: programming and controlling the dguard system (emergency, GPS, departure times, comfort levels); native iOS/Android.
QuickDoor - Digital Access Control
Development of an innovative access control app for gyms and sports facilities. The QuickDoor app enables members keyless access to various areas of the fitness center such as main entrance, side entrance, and underground parking. The app displays all relevant information such as operator ID, location, and WiFi credentials.
ESYLUX Smart Home App
Continuation of the ESYLUX smart home app (Xamarin, migration to .NET MAUI): lighting and automation control; project and device management. Clear, responsive UI for connected ESYLUX devices.
Chop-E AI Cooking Assistant App
Chop-E is an AI cooking assistant for iOS and Android. The app helps users with recipe search - by ingredients, by dish, or random selection. Modern UI and smart recommendations provide an engaging cooking experience.
identPro Warehouse App
IdentPro is a leader in warehouse optimization specializing in automated material tracking in production and warehousing. We received the commission from IdentPro GmbH to develop an app that enables manual inbound, outbound, and relocation of products. We used the IONIC framework for development and optimized the app for use with ZEBRA devices.
SAGASU Dating App
For Digital-meets GmbH, we developed SAGASU, a dating app that sets itself apart from classic dating apps: the matching partner is searched via Bluetooth in the immediate vicinity, making SAGASU perfect for finding matches in clubs, discos, large events, or wherever many people come together.
FeverApp
Development of FeverApp to support parents in caring for feverish children. The app helps parents document and monitor fever symptoms, strengthens their own thinking and intuition, and serves as a valuable basis for discussion with the doctor. Developed in cooperation with the University of Witten/Herdecke and the German Federal Ministry of Education and Research.
CSI Stuttgart App
The portal for buying and selling industrial electronics offers customers and dealers the ability to trade new and used industrial electronics components from all manufacturers via apps and website. The backend provides extensive management functions, from article management to customer management to invoice and order creation.
Hubit Charity Run App
HUBIT Media Coach e.V. organizes charity runs to raise funds for strengthening media literacy among children and young people. We developed a Flutter-based app that allows participants to register for the event and record and submit their performance.
Metropol FM Radio App
Development of a modern radio app for Metropol FM Berlin. The app enables users to listen to the radio station live, get information about current songs, and interact with the station. With an elegant user interface, playback controls, and additional features like favorites lists, the app provides an enhanced listening experience for fans of the station.
TILSBERK Navigation App
The TILSBERK Head-Up Display brings information directly into your field of vision without restricting it. We developed the iOS and Android app that displays information such as speed, navigation, incoming calls, TILSBERK charge status, time, and more on your TILSBERK Head-Up Display via Bluetooth. We recently added GPX import functionality to the app.
APPICS Social Media App
Development of an innovative social media platform based on blockchain that enables content creators to be rewarded for their content. The APPICS app combines social media with cryptocurrency, allowing users to earn tokens through likes, comments, and shares. With an elegant, user-friendly interface, the app offers all the features of modern social networks.
FROMM Keep it Smart App
Development of an Android app for managing FROMM strapping devices (P328 S and P329 S) via Bluetooth Low Energy. The app provides device overview with serial numbers and firmware versions, battery status monitoring, detailed strapping statistics, effortless firmware updates, and access to user manuals and spare parts lists.
Radio Ostfriesland App
Development of a radio streaming app for Radio Ostfriesland, the regional radio station for East Frisia. The app enables live streaming of the radio program, provides current news and program information. With intuitive controls, listeners can receive the station on FM 94.0 (Aurich), 87.7 (Emden), and 103.9 (Leer) on the go.
Tide & Tee App
Flutter app for iOS and Android: Tide & Tee is an in-house product by Groenewold IT Solutions—visitors on the North Sea coast get tides, weather, and tea culture for an East Frisia vacation in one app, conceived and built by us in Germany (Made in Germany), not as a client commission.
B.e.s.t. Akyol Store App
Development of a B2B ordering app for iOS and Android for B.e.s.t. Akyol Handels GmbH. The app enables business customers such as kiosk operators, beverage markets, and hospitality businesses to easily order beverages, confectionery, and packaging materials. With barcode scanner, current offers, and clear product categories.
LEDATRONIC WiFi App
Development of the free LEDATRONIC app for smartphones and tablets for controlling the LEDATRONIC WiFi combustion air control for LEDA stoves. The app clearly displays all information and functions and automatically initializes connected components such as LUC2, KS04, or ZAE.
Your App Project
Let us discuss your app idea
Whether native iOS/Android app, cross-platform with Flutter or React Native – we advise you on the optimal technology and develop your tailored solution.
Knowledge & Answers
Frequently Asked Questions About Mobile App Development
Technology & Platforms
Native app or cross-platform – which is better?
Native (Swift/Kotlin) offers best performance and access to all device functions – ideal for complex apps, gaming, or hardware integration. Cross-platform (Flutter, React Native) saves budget for apps with standard functionality. We advise you on the optimal choice.
Which cross-platform technology do you recommend?
Flutter for new projects focused on performance and unified UI. React Native if your team knows JavaScript/React or web components need to be reused. Both technologies deliver excellent results today.
Do you develop for iOS and Android simultaneously?
Yes. With cross-platform development (Flutter, React Native), one codebase covers both platforms. With native development, iOS and Android teams work in parallel. In both cases, we launch simultaneously.
Need technology consulting?
We help you select the right app technology for your project.
Thorsten Frieling – Project Management
Development Process
What does an app project look like?
1. Discovery: requirements, user stories, wireframes. 2. Design: UI/UX with prototyping. 3. Development: agile sprints with regular demos. 4. Testing: QA, beta testing, bug fixing. 5. Launch: store submission and go-live. 6. Maintenance: updates and further development.
Are we involved during development?
Absolutely. You get access to test versions (TestFlight/Firebase), see sprint results every 2 weeks, and can provide feedback at any time. Agile development thrives on close collaboration.
Do you also handle the backend?
Yes, we develop the complete system: app, backend API, admin panel, and cloud infrastructure. Everything from a single source ensures smooth integration and clear responsibilities.
Costs & Timeline
What does app development cost?
Simple app (MVP): from EUR 20,000 plus VAT. Mid-complex business app: EUR 40,000-80,000 plus VAT. Complex enterprise app with backend: EUR 80,000-200,000+ plus VAT. Cross-platform saves approx. 30-40% compared to two native apps.
How long does development take?
MVP/simple app: 2-3 months. Mid-complex app: 4-6 months. Complex app with extensive backend: 6-12 months. The exact duration depends on the feature scope and your feedback speed.
Are there ongoing costs after launch?
Yes: backend hosting (typically EUR 100-500/month plus VAT), maintenance and updates (10-20% of development costs/year plus VAT), Apple Developer Account (EUR 99/year), Google Play (one-time $25). We offer transparent maintenance contracts.
Cost estimate for your app?
We create a transparent cost plan after the briefing.
Bjoern Groenewold – Managing Director
Design & Usability
Who designs the app?
Our UX/UI team. We start with user research, create wireframes, then visual design with prototypes in Figma. You see and test the design before development – changes are still affordable at that point.
Can we incorporate our corporate design?
Of course. We integrate your brand colors, typography, logo, and visual language. The app becomes a consistent element of your brand identity – adapted to the respective platform guidelines (iOS Human Interface, Material Design).
How do you ensure good usability?
Through user-centered design process: personas, user journeys, prototyping, and usability tests with real users. We measure success by metrics like task success rate, time-on-task, and user satisfaction.
Publishing & Maintenance
Do you handle store submission?
Yes, completely. We create store assets (screenshots, videos, texts), submit to Apple and Google, and guide you through the review process. You only need developer accounts (we can also set those up for you).
What if Apple/Google rejects the app?
It happens but is rarely critical. We know the guidelines and avoid common mistakes. If rejected, we analyze the feedback, adjust, and resubmit – usually resolved within a few days.
How are updates deployed?
Through the stores – users receive update notifications. For urgent fixes, we use Code-Push (over-the-air updates without store review). Regular updates keep the app compatible with new OS versions.
Can we further develop the app ourselves later?
Yes. You receive complete source code and documentation. We hand over cleanly and train your team if needed. However, many clients use our maintenance contracts for continuous development.
Ready for your app?
Let us talk about your app idea and plan the next steps.
Thorsten Frieling – Project Management
More References & Services
Mobile App Development: From Idea to Successful App
Mobile apps are at the core of many companies' digital strategy today. They enable direct access to customers, increase employee productivity in the field, and create new business models that would be unthinkable without mobile devices. Our mobile app references show the breadth of successful projects we have implemented for companies across a wide range of industries – from consumer apps with hundreds of thousands of downloads to specialized B2B applications for industrial use.
For technology selection, we choose the best approach for each use case. For maximum performance and full access to device functions, we develop natively with Swift for iOS and Kotlin for Android. When a unified codebase for both platforms is more economical and app requirements allow it, we use cross-platform frameworks like Flutter or React Native. We make this decision together with our clients based on a thorough analysis of functional requirements, budget, timeline, and long-term maintenance strategy.
Each of our app projects follows a structured process: from the initial concept phase with UX workshops through prototyping and iterative development to launch in the app stores and long-term further development. The user experience is particularly important to us. A technically perfect app that nobody likes to use misses its goal. That is why we invest considerable time in user research, wireframing, and usability tests before we start implementation.
The projects shown here include, among others, e-commerce apps with integrated payment processing, fitness tracking applications with wearable connectivity, logistics apps for real-time shipment tracking, IoT control apps for smart home devices, and enterprise apps for field sales teams. Each of these applications was individually tailored to the requirements of the respective company and is successfully in use today.
What our clients particularly appreciate: We think beyond the pure app code. Backend architecture, API design, push notification strategies, analytics integration, and thoughtful app store optimization are all part of our complete package. Because an app is only as good as the ecosystem it runs in. Our developers work exclusively from Germany, ensuring short communication paths, data privacy compliance, and cultural understanding of the German market.