Android App Development · Remote worldwide

Android apps, built solo.

I plan, design and build Android apps solo — usually cross-platform with React Native (one codebase for Android and iOS), with my own backend, all the way to the Google Play Store. Backed by published Play Store apps. Remote worldwide, from Germany (CET).
01 — App Development

Android Apps & Cross-Platform

Concept & UX Design
React Native — one codebase
Backend myself — Supabase
Google Play submission & review
Maintenance & Android updates
Many ‚app freelancers' only deliver the design — for the actual coding you then need a second person. I'm the exception: I build the app from front to back, alone. The interface with React Native (one codebase for Android and iOS), my own backend (Supabase) behind it, and I ship it to the Google Play Store myself. Backed by my own published Play Store apps — not by promises.
PROCESS

How your Android app comes to life

01

Concept & UX

We clarify what the app needs to do, for whom, and cut an MVP. The user flow is set before a single line of code is written.
02

Design

UI in a Material look that feels right on Android. You see the screens before they're built.
03

Code + Backend

Cross-platform development with React Native, database & logic (Supabase) behind it — all from one hand.
04

Google Play

Submission, Play Console setup, launch. Adjustments for new Android versions included.
THE ANDROID APPS

Live on the Google Play Store

My published apps on Google Play — built solo, from concept to store approval. Tap to open the app on Google Play.
Altitude
Altimeter · Android
Altitude iOS-App von Carsten Sachse – Höhenverlauf GPS und Barometer
NetRadar Pro
Network Scanner · Android
NetRadar Pro Android-App von Carsten Sachse – Netzwerk-Scanner
02 — Full-Stack

Frontend AND Backend

React Native (Android + iOS)
Supabase / my own backend
Play Console & Release
Push, offline, device sensors
No second developer needed
The difference from many app freelancers: I don't just build the visible app, but the database behind it too. Frontend, backend and Play Store release all from one hand — you don't need a second person for the coding.
03 — Agency or Freelancer

Why a solo developer is often the better choice

One consistent point of contact
No project-manager overhead
Direct, fast communication
Fair solo rates
You talk to the person who builds
Agencies have teams and redundancy — and the overhead that comes with it. With me you talk directly to the developer, no detours. For focused Android apps (MVP to mid-range) that's faster and cheaper. For very large projects I'll be honest: a team makes more sense.
04 — Maintenance

After launch

Android update adaptations
Bugfixes & Play updates
New features
Backend monitoring
Time-based or retainer
Operating-system updates regularly force apps into code changes. I keep your app running, fix bugs, build new features — and take care of the backend behind it. Billed by time or as a retainer.
MVP-First

Start small, get real feedback, then scale

3–4 core features first
Manageable initial investment
Real user feedback before expensive extras
Good apps start as an MVP — a base version with the most important features. It saves budget, gets your app into the Play Store faster, and delivers real user feedback before expensive add-ons get built.

Frequently Asked Questions

Do you build the backend too, or just the design?
Both. I'm full-stack — I build the app interface with React Native AND the database and logic behind it (Supabase). You don't need a second person for the coding.
What does an Android app cost?
Highly dependent on scope. A focused app starts in the mid four-figure range; a complex backend or a parallel iOS version accordingly more. Plus the one-time Google Play developer account (€25 one-time). In the first call I estimate effort and tools transparently. In depth: What does an app cost?
Do you really get apps into the Play Store?
Yes — for example, NetRadar Pro and Altitude are live on Google Play. Getting an app cleanly through the Play Console review is its own discipline alongside coding, and I do it myself.
Native (Kotlin) or cross-platform?
It depends on the goal. Cross-platform with React Native gives you Android and iOS from one codebase — faster and cheaper. Native when maximum performance or special Android features are needed. I'll advise honestly on what fits your budget.
How long does an app take?
A focused MVP often in a few weeks, larger apps accordingly longer. After the first call I'll give you a realistic estimate.
Do you build iOS apps too?
Yes — with cross-platform (React Native) the iOS version comes from the same codebase, and I also build native iOS apps in Swift. More on that: Native iOS app development. Need a web app in the browser instead of a native app (no store)? Then have a look at Software & web apps.

Ready to bring your app to the Play Store?

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