We develop apps that achieve goals
Enterprise quality meets boutique agility: we develop apps with clear architecture that have been proven to deliver business impact and growth.
For ambitious start-ups, medium-sized companies and corporations that don't have time for ‘second attempts’.
Success stories
with measurable results
GUTEFRAGE.NET / HIGHFIVVE
Anyone looking for an app development agency will be delighted with Johnny Bytes. We held a workshop with gutefrage.net on the topic of apps and app SDKs and had a very in-depth and detailed exchange. The knowledge and experience that Johnny Bytes brings to the table is remarkable.
Nepomuk Seiler
JUST HEALTH GMBH
Johnny Bytes was a complete game-changer for our digital health app. Their expertise is outstanding; they got up to speed in record time and drove our development forward with decisive technical insights. We absolutely recommend them for any complex app project.
Maximilian Roederstein
EMPOWER GMBH
In the development of our software suite, we faced complex challenges. Johnny Bytes provided more than just strategic advice; they actively supported our development process and were decisive in its successful execution.
Stephan Kuhnert
APOTHEKE LUX 99
We wanted more than just an off-the-shelf e-prescription app; we needed a solution perfectly tailored to our pharmacy's specific workflows. Johnny Bytes' expertise in digital health was clear as they understood and executed our vision in perfect detail. The result is our very own app, which is a tremendous asset for both our customers and our team. For anyone seeking a truly custom solution, you've come to the right place.
Tobias Loder
READFY
With Readfy, up to half a million users regularly read over 130,000 ebooks for free. Johnny Bytes took over the apps for iOS and Android from our previous nearshore partner and not only brought them and the backend up to date in a very short time, but also ensured that in-app sales increased by 500%.
Philipp Ortmaier
PAGOPACE
We were already able to offer our customers good hardware with our payment ring. However, Johnny Bytes helped us to build the perfect complementary software to take our product to the next level. We were kept up to date at every stage of the app development and were able to make requests immediately. With the new app, we can also sell our rings in retail stores, as customers can link their rings directly to their payment card on their cell phone.
Steffen Kirilmaz
FIRST AVENUE
Johnny Bytes has taken over the development and support of our guest information system TIPPTHEK and migrated it to a modern and sustainable architecture in a very short time. This allows us to install TIPPTHEK in thousands of South Tyrolean accommodations and provide up to 35,000 tourists a day with personalized information about their accommodation and the surrounding area.
Michael Hölzl
STAZZLE
An agile team for whom customer satisfaction is just as important as quality, the Johnny Bytes team understands communication and requirements, asks the right questions, has a sense of humor and adheres perfectly to schedules. A strong partner that we recommend without reservation. Thank you for your support!
Tasso Mitsarakis
KOOPERATIONEN MIT HOCHSCHULEN
Together with Johnny Bytes, FH Aachen regularly conducts practice-oriented research projects as part of the Digital Lab. Most recently, prototypes for Alexa skills and AI-supported tourism solutions were created in this context. These projects are always an enrichment for our students, the university and the company.
Prof. Dr. Mathias Eggert
For companies that want to turn an idea into a scalable product.
We treat your project as if it were our own – with strategic foresight and a hands-on approach.
That's why we don't just develop, we actively contribute ideas and take responsibility. Because that's the only way we can make your idea economically viable and achieve success together.
Not just apps,
but complete digital products
Cross-platform and native apps, high-performance backends and intelligent automation – all from a single source.
We build the complete infrastructure that will make your idea a success.The result: a digital product in which the front end, back end and intelligently deployed AI work together seamlessly.
Android & iOS development
Flutter or fully native – depending on what your product needs. Fast time-to-market without compromising performance.
Web development
Development of powerful, efficient and visually appealing web applications.
Backends & APIs
Scalable APIs, database design and cloud infrastructure. Built for millions of requests or even just for the MVP.
AI Integration
Not buzzword AI, but measurable automation via intelligent chatbots to data-driven recommendations.
The Johnny Bytes App Engineering Framework:
From Strategy to Growth
We take responsibility – not just code.
We accompany you on the journey from the initial idea to the launch of your customised, scalable app. Together, we define goals, develop concepts and implement them in the optimal solution. We value transparent and open communication, regular feedback and an agile way of working to ensure that we are always developing in the right direction.
01
Strategy & risk minimisation
In our discovery layer, we validate requirements, risks and genuine customer benefits. This ensures that we only develop what has a measurable impact.
02
Concept & Architecture
In our architecture layer, we develop the technical guidelines that will lead your product to success. This includes concepts for scalability, security, deployment strategies, and build vs. buy decisions. This helps us prevent rewrites later on.
03
Efficient development
Our build squads deliver features in parallelised streams — quickly, reliably and with clear documentation. Short feedback cycles and agile iterations enable high delivery speeds without compromising on quality.
04
stability guarantee
Automated testing, performance checks and security scans minimise release risks. Our hardening layer ensures that functions not only work, but also scale stably.
05
Rollout & Go-Live
We ensure a smooth rollout and support the go-live in all areas.
06
Growth & Long-Term Partner
An app doesn't just end up in the app stores: after launch, we actively optimise conversion flows, retention and feature adoption. Data-driven experiments ensure that your product continuously delivers measurable added value for your business.
Selected reference Projects
Not sure whether we are the right partner for you? We are happy to let our references and clients speak for us.
OnkoPass
Cancer Care app for outpatient cancer treatment
OnkoPass offers digital support and improved communication between doctors and patients – for personalised care and less administrative work.
Pharmacy App
App for the german pharmacy sector
Secure and user-friendly: redeem e-prescriptions on your smartphone.
Magic Ads
AI for publishers: Better sales through ‘magical’ banners
For a leading regional publisher, we created an AI driven innovative advertising app that automatically creates display banners.
Readfy
E-books for everyone - free and unlimited
Innovation and stability for the number 1 free e-book reader app.
Pagopace
Unique companion app for NFC wearables
Opening up new sales markets and increasing customer satisfaction for a payment wearable.
Start your app project
with Johnny Bytes
Discuss your app idea in a non-binding and free strategy meeting.
Get clarity on feasibility, costs, and timeframe - and start your project with experts.
Johnny Bytes is an app development agency based in Cologne, Germany, that builds tailor-made apps for iOS, Android and the web – from the first idea to long-term growth. As a specialised app agency, Johnny Bytes combines enterprise-grade quality with boutique agility: cross-platform development with Flutter, native iOS and Android apps, scalable backends and APIs for millions of users, and the practical integration of artificial intelligence and custom RAG systems. Its unique "Build Squad" model puts dedicated, agile expert teams to work for start-ups, mid-sized companies and corporations, following a clear product-first approach and the principle of security by design. The agency has particular experience in regulated markets such as health and MedTech, as well as in modernising legacy software and complex backend infrastructure. From the first strategy session to ongoing development after launch, Johnny Bytes supports projects end-to-end – the result is scalable digital products that deliver measurable business impact.
