iOS App Agency from Cologne

iOS app development for iPhone & iPad

From the first idea through UI/UX and development to the App Store launch, we support your iOS app end-to-end.

Native with Swift and SwiftUI or cross-platform with Flutter: together we choose the approach that fits your product – for apps that feel 100% Apple.

iOS app development
Native quality for the Apple ecosystem

Why iOS development?

The App Store is the highest-grossing market for mobile apps – and iOS users expect quality. We build iPhone and iPad apps that live up to that expectation.

Premium user experience: Swift and SwiftUI deliver smooth animations, short loading times and an interface that feels exactly like Apple.

High-value audience: on average, iOS users spend significantly more on apps and in-app purchases – ideal for premium and subscription models.

Security & privacy: Keychain, Face ID and strict sandboxing – essential wherever sensitive data is processed, for example in health and MedTech.

Proven in production: from PAGOPACE to the e-prescription integration to Piening Connect – our apps are used by tens of thousands of iOS users every day.

Your iOS agency for the entire product lifecycle

Our iOS services

From concept to operation: we cover the complete lifecycle of your iOS app – or strengthen your existing team with our expertise.

iOS app development

Building your iPhone or iPad app with Swift & SwiftUI or Flutter – from MVP to a scalable enterprise solution.

API & backend integration

Connecting REST and GraphQL APIs, push notifications via APNs, in-app purchases and Apple frameworks such as HealthKit or MapKit.

UI/UX the Apple way

Interfaces built to the Human Interface Guidelines: dark mode, Dynamic Type and accessibility included – on-brand and pixel-perfect.

iPad, Apple Watch & widgets

More than iPhone: we bring your app to the iPad, the Apple Watch and the home screen – with widgets, App Clips and Live Activities.

Testing & App Store launch

Automated tests, TestFlight betas and a review-proof App Store launch – including store listing and release management.

iOS consulting & team extension

Architecture consulting, code reviews or experienced iOS developers for your team – flexible, as needed.
At a glance

The advantages of native iOS apps

iOS stands for quality, security and an exceptionally loyal user base. These four advantages make the case for the Apple platform:

01

Premium user experience

Native iOS apps are fast, smooth and feel exactly the way Apple users expect. That pays directly into ratings, retention and conversion.

02

High-value audience

On average, iOS users spend significantly more on apps, subscriptions and in-app purchases than on other platforms – ideal for premium products.

03

Security & privacy

Face ID, Keychain and a strict sandboxing model protect sensitive data – the foundation of trust, especially in regulated markets.

04

Deep system integration

Siri, widgets, HealthKit, NFC and CarPlay: we use Apple's frameworks so your app can do more than live on its own island.

Native with Swift or cross-platform with Flutter?

In a free initial consultation we will assess together which approach is right for your project – technologically and economically.

Book a free consultation

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, Head of Engineering, gutefrage.net
Nepomuk Seiler
Head of Engineering, gutefrage.net
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, Co-Founder, JustHealth GmbH
Maximilian Roederstein
Co-Founder, JustHealth GmbH
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, Managing Director, empower GmbH
Stephan Kuhnert
Managing Director, empower GmbH
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, Inhaber, Apotheke LUX 99
Tobias Loder
Inhaber, Apotheke LUX 99
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, CEO, readfy GmbH
Philipp Ortmaier
CEO, readfy GmbH
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, CEO, PAGOPACE GmbH
Steffen Kirilmaz
CEO, PAGOPACE GmbH
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, CEO, First Avenue GmbH
Michael Hölzl
CEO, First Avenue GmbH
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, Product Owner, stazzle
Tasso Mitsarakis
Product Owner, stazzle
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, FH Aachen
Prof. Dr. Mathias Eggert
FH Aachen

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.

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