Ship your mobile app MVP on iOS and Android in 4 weeks
Greta is a hands-on MVP development agency that builds React Native apps running on both iOS and Android from a single codebase. Every project includes push notifications, offline sync, biometric login, and full App Store and Play Store submission. From wireframe to live listing in one month.
Most mobile agencies quote 6–12 months and six-figure fees. We work differently. We lock the MVP scope tight, assign a dedicated team, and run a 4-week sprint. Real users download your app before your runway runs thin. Starting from £10,000.
4 weeks
Delivery timeline
iOS + Android
One React Native codebase
Push alerts
FCM + APNs setup
£10k
Starting price
Why most mobile MVPs take too long — and what to do instead
The average time from idea to App Store listing for a startup mobile app is 6 to 12 months. The main reason? Teams try to build every feature they can imagine before launching. In reality, fewer than 20% of those features survive first contact with real users. The rest is wasted money and time.
A second trap is platform paralysis. Should you build for iPhone first? Android first? Both at once? Meanwhile, your competitors ship. React Native (a tool that writes one set of code for both phones) solves this. It shares roughly 90% of code between iOS and Android. That means you reach both audiences simultaneously for roughly the same cost as a single build.
The Greta model attacks both problems head-on. We scope only the features that test your core idea — think of it like a first pancake to test a recipe before baking the whole batch. Then we use React Native to ship iOS and Android in parallel. The result is a live, testable app in 4 weeks. You get real user feedback before you commit to a longer build. If you want to understand what an MVP is and why this approach saves founders money, we explain it in full detail.
Not every mobile app needs custom code, either. Some founders are better served by a no-code MVP first — we can help you decide which route fits your stage and budget.
Ready to build?
Let's bring your idea to life. Fast, affordable, and production-ready.
What is included in every Greta mobile MVP
Every mobile startup MVP we build ships with these ready-to-use features — not rough demos, but real integrations your app needs to work properly in users' hands from day one.
React Native for iOS & Android
One TypeScript codebase that runs on both platforms. We use Expo or the bare workflow depending on your needs, and set up a CI/CD pipeline (think: an automatic delivery conveyor belt for your code) so you can push updates quickly after handover.
Push notifications — FCM + APNs
Firebase Cloud Messaging for Android and Apple Push Notification service for iOS. Both are wired to your backend so you can send alerts, reminders, and silent background updates. Delivery tracking and opt-in/opt-out screens are included.
Offline-first data sync
Your app saves data locally on the phone when there is no internet. When the connection comes back, it syncs automatically — like a notebook that uploads itself when you get to Wi-Fi. Critical for field workers, drivers, or anyone in low-signal areas.
Biometric authentication
Face ID, Touch ID, and Android fingerprint login built in. Sensitive tokens are stored in the phone's secure chip — not a plain text file. Users get a fast, safe login experience from day one.
In-app purchases & subscriptions
Apple and Google payment systems integrated via react-native-iap or RevenueCat. Includes server-side receipt checking, subscription lifecycle events, and a restore-purchase button — everything the app stores require.
Deep linking & universal links
A deep link is like a shortcut that opens a specific screen inside your app straight from an email or web page. We configure this so your marketing messages, push notifications, and landing pages all drop users exactly where you want them.
BUILD IT FAST
Ready to ship your mobile app in 4 weeks?
Tell us your idea and we'll scope an MVP that reaches real users on iOS and Android this month — not next quarter.
TALK TO A FOUNDER
Not sure where to start?
Book a 20-minute call. We'll map out your scope, tech stack, and go-to-market plan — for free.
Our 4-week mobile MVP build process
Every project follows 5 clear steps. You always know what is happening and when. No surprises, no disappearing developers. If you have built a marketplace MVP or an ecommerce MVP before, this process will feel familiar — just faster.
- 01
Discovery & mobile scope alignment (Days 1–3)
We talk to you and your team, map out the main things users will do in the app, and cut everything that is not needed to test your core idea. You get a written scope document, a ranked feature list, and a simple diagram showing how the app, API, and cloud fit together.
- 02
UI/UX design for mobile (Days 4–7)
Our designers build every key screen in Figma (a design tool — like a digital sketchpad). We follow Apple and Google's own design rules so the app feels native. You see a clickable prototype and give feedback before we write a single line of code.
- 03
React Native development (Days 8–21)
Engineers build the screens, navigation, and all the integrations in parallel. Push notifications, offline sync, and login are built in week 2 alongside the core screens. We post daily updates on Slack and share a testable build on your phone every 48 hours.
- 04
QA across devices & OS versions (Days 22–26)
We test on real phones — iPhone 13 through 16 (iOS 16–18), Samsung Galaxy S-series and mid-range Android (Android 12–14). Push notifications, offline mode, biometric login, deep links, and payment flows all get verified before submission.
- 05
App Store & Play Store submission (Days 27–28)
We submit to both stores, write all the descriptions, and handle any questions from Apple or Google's review teams. You get the full handover pack: your source code, CI/CD setup guide, backend settings, and a post-launch monitoring dashboard.
Who we build mobile MVPs for
Most of our clients are founders with a clear idea but no technical team yet. They need a real app — not a website dressed up to look like one — so they can show investors or get early users. If that is you, book a free call and we will tell you honestly whether a mobile MVP is the right move or whether a web app would be faster.
We also work with early-stage teams who already have a web product and want to expand to mobile. Maybe you have a SaaS product (software people pay a monthly fee to use) that your customers want on their phones. We can build a React Native version alongside your existing web app without rebuilding everything from scratch.
If you are building something with buying and selling — like a marketplace where two groups of people transact — a mobile app dramatically increases engagement compared to a mobile website. We have built marketplace MVPs for both iOS and Android that include payments, reviews, and real-time messaging in a single 4-week sprint.
Mobile app MVP options compared — 2026
| Option | Cost | Timeline | Support |
|---|---|---|---|
| Traditional agency | £80,000–£200,000 | 6–12 months | Extra cost |
| Freelancer | £20,000–£60,000 | 3–9 months | You manage it |
| No-code tools | £0–£500/month | Weeks | Very limited |
| Greta | From £10,000 | 4 weeks | Included |
No-code tools are a good starting point — see our no-code MVP development page for when that route makes sense. But if you need a real native app experience, custom code wins every time.
BUILD IT FAST
From concept to App Store listing in 28 days
We handle design, development, push notification setup, and full store submission — so you can focus on acquiring your first users, not managing developers.
TALK TO A FOUNDER
Not sure where to start?
Book a 20-minute call. We'll map out your scope, tech stack, and go-to-market plan — for free.
Frequently asked questions about mobile app MVP development
Can you really build a mobile app MVP in 4 weeks?+
Yes — for a focused MVP with a well-defined scope. Think of an MVP (minimum viable product) as the first version of your app that does one thing really well. We build only what is needed to test your core idea, not a full-featured app. Using React Native means we ship one codebase for both iOS and Android at the same time, cutting development time roughly in half compared to building two separate apps. Teams that add features mid-project push the timeline out; those who trust the scope hit 4 weeks consistently.
Why React Native instead of Swift/Kotlin or Flutter?+
React Native lets us build iOS and Android from one codebase. That halves the engineering work and makes it much simpler for your team to maintain after handover. It has strong community support and performs well enough for the vast majority of MVPs. Flutter is a solid alternative but has fewer developers available. Pure native (Swift for iPhone, Kotlin for Android) is the right choice only if your app needs maximum graphics performance — for example, a 3D game or augmented reality experience. That is rarely what an MVP needs.
What does App Store and Play Store submission involve?+
We set up your Apple Developer account and Google Play Console (or use your existing ones), handle all the technical signing steps, write the store descriptions, create the required screenshots, check your privacy policy meets current rules, and submit the app for review. Apple usually takes 1–3 business days; Google is typically under 24 hours. If either store rejects the app, we handle the response and resubmission — it is all included in the project.
Is offline-first sync really necessary for my MVP?+
It depends on your users. If they work in places with weak internet — delivery drivers, site workers, nurses in basements — offline mode is essential. For apps that need live data (stock prices, real-time chat) a full offline mode may be overkill for an MVP. We assess this in the discovery session and give you an honest recommendation based on your actual user scenarios.
What is included in the £10,000 starting price?+
The starting price covers a scoped MVP: discovery session, Figma UI design, React Native build for iOS and Android, push notification setup, basic authentication (email/password plus biometric), a backend API (the engine that powers your app's data), QA on real devices, and submission to both stores. Things like in-app purchases, complex offline sync, or custom animations are quoted separately. Most mobile MVPs land between £10,000 and £30,000 — we confirm the exact number after the discovery session.
Sources & further reading
External references cited on this page.
App Store Review Guidelines — Apple Developer
Official Apple guidelines covering submission requirements, privacy, in-app purchases, and design standards for iOS and iPadOS apps.
Google Play Developer Policy Center
Google's authoritative policy documentation for Android app submissions, including data safety, monetisation, and content standards.
React Native Architecture Overview — Meta Open Source
Official documentation explaining the React Native New Architecture (JSI, Fabric renderer, TurboModules) that underpins modern cross-platform mobile apps.
Firebase Cloud Messaging documentation — Google
Technical reference for FCM, the cross-platform messaging solution used to deliver push notifications reliably on Android and iOS.
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Your mobile app could be live in 4 weeks from now
Get a scoped mobile minimum viable product on iOS and Android, complete with push notifications, offline sync, and App Store submission — for a fraction of what a traditional agency charges and in a quarter of the time. Book a free 30-minute discovery call to see exactly what we can build for you.
Free 30-minute discovery call. Real pricing within 48 hours.