# App Development for iOS, Android & Web

> Native apps for iOS, Android, and web from one codebase. From a 12-week MVP to a production app.

An app for iOS and Android realistically costs between 25,000 and 80,000 euros for a solid MVP in 2026, with 8 to 12 weeks of development time. That's the honest entry point; enterprise apps with deep system integration reach six- to seven-figure budgets.

By MVP we mean the smallest version of the app that solves a clear problem and runs on both platforms. No feature pile-up, no three-month research phase. An MVP is not a prototype or a demo: it ships to the App Store, gets real users, and delivers data for the next iteration. Typical MVP scope: authentication, two to three core screens, backend integration, push notifications.

Native or cross-platform? For over 80 percent of business apps, React Native with Expo is the right choice: one codebase, one design language, 30 to 40 percent cost savings compared to native iOS/Android dual development. Instagram, Shopify, Discord, and Microsoft Office run React Native in production. We only recommend native when platform-specific features are required, such as complex camera pipelines, ARKit/ARCore, or performance-critical animations in games.

Store submission is its own craft. Apple typically reviews within 24 to 48 hours, Google within a few hours to one day. The common rejection reasons have been the same for years: missing privacy policy links, incomplete metadata, dummy content in the release build, or features behind a login the reviewer does not have. We prepare screenshots, store copy, app icons, and privacy labels and handle submission, including the typical one or two correction rounds.

We build with React Native 0.78 and Expo SDK 53, connected to a .NET 10 backend. The backend runs on Fragon Cloud in Nuremberg, GDPR-compliant under Art. 28 GDPR, with no third-country transfers.

## Features

- React Native 0.78 with Expo SDK 53
- Native performance on iOS 15+ and Android 9+ (API 28)
- Responsive web version from the same codebase
- Access to camera, GPS, push, and biometrics
- OTA updates via EAS Update
- .NET 10 backend on Fragon Cloud Nuremberg

## From MVP to Production App

1. **Concept & Design**: What should the app do? We clarify features, prioritize by impact, and design UI following Apple HIG and Material Design. Mobile-first, but web-ready.
2. **Development**: One codebase, weekly builds via EAS Build. You test on real devices and in the browser. Progress is always visible.
3. **Backend & Integration**: .NET API, integration with existing systems, push notifications via Expo Notifications, auth via OAuth or your own identity provider.
4. **Store Release and Operation**: App Store, Play Store, web deployment. We handle screenshots, store copy, privacy labels, and review rounds. Operation and OTA updates optional.

## Benefits

- **One codebase, three platforms**: Development, testing, and maintenance happen once. That saves 30 to 40 percent compared to native dual development.
- **Consistent experience**: Your users get the same features on iPhone, Android, or browser. No platform lags behind.
- **Fast updates**: Web updates are live immediately. Mobile updates roll out via EAS Update without store review, as long as only JS code is affected.

## FAQ

**What does an app MVP realistically cost?**
15,000 euros downward is a hard limit. A solid MVP with iOS and Android from one codebase typically lands between 20,000 and 40,000 euros with 8 to 12 weeks of development. That includes auth, two to three core screens, backend integration, push notifications, and store submission.

**React Native, Flutter, or native: which is better?**
For 80 percent of business apps, React Native or Flutter is the right choice: one codebase, 30 to 40 percent cost savings compared to native dual development. Native only for platform-specific features such as complex camera pipelines or GPU-intensive games. We primarily use React Native with Expo.

**Is cross-platform a compromise on performance?**
Not for business apps, portals, and e-commerce. React Native renders real native components on mobile; users notice no difference. Instagram, Shopify, and Discord use the same technology. For games and GPU-intensive applications, we recommend Unity or Unreal Engine.

**Can we build just mobile or just web?**
Yes. The architecture is flexible. You can start with mobile and add web later, or the other way around. We structure the codebase so that extending is not a rewrite.

**We already have an app. Can you take it over?**
Depends. Existing React Native or Expo apps are usually straightforward to take over. For native iOS/Android apps, a rebuild in React Native is often more economical than maintaining two codebases. We audit the codebase over 2-3 days first.

**How does store submission work?**
We prepare screenshots, store copy, app icons, and privacy labels and handle submission at Apple and Google. Apple typically reviews in 24 to 48 hours, Google within hours. The typical one or two correction rounds are covered in the fixed fee.