Mobile App Development Company for iOS and Android

We help you decide whether your app should be cross-platform (Flutter or React Native), a PWA or, in specific cases, native, and we build all of it: design, backend and API, release on the App Store and Google Play, push notifications and maintenance. With the team that has been building custom software since 2009.

Tell Us About Your App Native, Cross-Platform or PWA
  • 1 codebase For iOS and Android with Flutter or React Native
  • 8-10 weeks An MVP with 5 to 8 screens
  • Since 2009 Building custom software
How we build: requirements, architecture, reviewed code, reversible deployment, measured performance and evolution with your team Every metric sets the next iteration 01 · Requirements What the businessneeds 02 · Architecture Documenteddecisions 03 · Code Reviewed andtested 04 · Deployment Automated andreversible 05 · Performance Core Web Vitals inthe green 06 · Evolution Your team asks, wedeliver
  1. 01 · Requirements What the business needs
  2. 02 · Architecture Documented decisions
  3. 03 · Code Reviewed and tested
  4. 04 · Deployment Automated and reversible
  5. 05 · Performance Core Web Vitals in the green
  6. 06 · Evolution Your team asks, we deliver
  7. Every metric sets the next iteration
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Definition

What Is Mobile App Development?

Mobile app development is the design, coding, release and maintenance of apps for iOS and Android phones and tablets, together with the backend and API that their data, users and notifications depend on.

There are three routes: native (one app in Swift for iOS and another in Kotlin for Android), cross-platform (a single codebase for both, with Flutter or React Native) and PWA (a website that installs on the phone, works offline and does not go through the app stores). Choosing well between them decides much of the cost, the timeline and the maintenance in the years that follow.

Summary

Executive Summary

What you should know before commissioning an app.

The first decision is not the technology but whether you need an app-store app at all. If your audience will not install it, or what you offer works well in the browser, a PWA costs less and ships sooner. If you need to be on the App Store and Google Play, reliable notifications or access to phone features, the usual answer is a cross-platform app: one codebase for iOS and Android, with Flutter or React Native. Two separate native apps are only justified in specific cases.

An app is not just screens. Behind it sits a backend and an API that store the data, manage users and permissions, send notifications and connect to your ERP, CRM or store. There are Apple and Google reviews to fit into the schedule, old versions of the app still on your users’ phones, and new iOS and Android releases every year. That is where budgets that only counted screens fall apart, which is why we plan for it from day one.

We do it all with one team: UX/UI design, app, backend, testing and release. We build the backend with the same approach as Nexo, our own platform, in production since July 2023 with its own API and live integrations.

  • 8-10 weeks MVP with 5-8 screens in Flutter or React Native
  • 12-16 weeks Full app with backend
  • €8,000-€15,000 Turning your website into a PWA

Key points

Native, Cross-Platform or PWA: Which One Suits You

We choose it with you during discovery, before quoting.

  1. 01

    Cross-Platform with Flutter

    A single Dart codebase that compiles to native code for iOS and Android, with an identical interface on both. A good fit when you are starting from scratch, want a fluid custom design and have no React team behind you. Full details in Flutter development.

  2. 02

    Cross-Platform with React Native

    A single TypeScript codebase using each platform’s native components. A good fit if your team already works with React or you want to share logic with your website, and it lets you ship fixes without another store review. More in React Native development.

  3. 03

    PWA (Progressive Web App)

    An installable website that works offline, is indexed by Google and does not depend on the app stores. A good fit for online stores, content and business tools. It has limits on iOS (storage, some APIs). Published prices in PWA development.

  4. 04

    Native (Swift and Kotlin)

    Two separate apps, one per platform. Only worth it for very heavy hardware use or requirements that demand it. If your case needs it, we will tell you during discovery; for specific phone features, we write the native module and use it from Flutter or React Native.

What's included

What Your App Development Includes

Everything an app needs to run in production, not just the screens.

  • UX/UI design of the flows and screens, with a clickable prototype before coding
  • iOS and Android app with Flutter or React Native, or a PWA if that suits you better
  • Backend and API: data, users, permissions and business logic, versioned so older app versions keep working
  • Integrations with your ERP, CRM, online store, payment gateway or in-house systems
  • Push notifications via Firebase Cloud Messaging and APNs, segmented from the backend
  • Offline mode and sync when the app needs it
  • Automated testing and testing on real devices before every release
  • App Store and Google Play release: listings, screenshots, review and launch
  • Error tracking and analytics so you know what breaks and what gets used

Why

The App Is Half the Job: Backend and API

What you do not see, and what decides whether the app holds up.

Almost every business app depends on a server: user accounts, synced data, payments, notifications and connections to other systems. We design the API first, with authentication, server-side permissions and versioning, because when you ship an update many users stay on the previous one for weeks. We build it in Laravel or Node.js depending on the project, with automated tests as in QA automation. It is the same work that sits behind Nexo, our own platform: multi-tenant, with an API and more than 10 live integrations.

api/v1/routes.php
// Versioned API: older apps keep working
Route::prefix('v1')->middleware('auth:sanctum')
->group(function () {
Route::get('orders', [Orders::class, 'index']);
Route::post('devices', [Push::class, 'register']);
});
  • Versioned API
  • Server-side Permissions
  • FCM + APNs Push

How we work

How We Build Your App

From discovery to an app that is live and maintained.

  1. 01

    Discovery and Technology Choice

    We work out what the app has to do, for whom and which systems it talks to. We decide with you whether it should be cross-platform, a PWA or native, and give you a fixed quote by phase.

    Before quoting
  2. 02

    UX/UI Design and Prototype

    Flows, screens and a clickable prototype. We test the essentials with users before writing any code.

    First weeks
  3. 03

    App and Backend in Iterations

    Feature-by-feature development, with test builds you can install on your own phone from the first weeks. Backend, API and integrations run in parallel.

    Iterative
  4. 04

    Testing and Release

    Automated tests and tests on real devices, store listings and submission to Apple and Google review, with review time built into the schedule.

    Before launch
  5. 05

    Maintenance and Evolution

    iOS and Android updates, dependencies kept current, error tracking and new features measured against usage data.

    Ongoing

Who it is for

Is It for You?

An app pays off when people will use it often and it solves something the website cannot solve as well.

Who it's for

  • Companies that need an app for their customers: orders, bookings, customer area, loyalty.
  • Field or shop-floor teams that need a tool on their phone, with or without a connection.
  • Startups and SaaS products that want to launch an MVP on iOS and Android from one codebase.
  • Businesses with a website or store that want an app-like experience without going through the stores (PWA).
  • Companies with an app that has lost its supplier or its maintenance.

Who it's not for

  • If what you need can be solved with a good responsive website: we will tell you, and you will save the cost of an app.
  • Games and heavy augmented reality experiences: they are not our specialty.
  • If you are after the cheapest possible template-based app: what we do is custom software with its own backend.

Deliverables

What Is Included and What Is Not

So you know what you get and what you pay for separately.

Included

  • UX/UI design and prototype of the agreed flows
  • iOS and Android app (or PWA) with the agreed scope
  • Backend, API and admin panel if the app needs them
  • Automated testing and testing on real devices
  • Preparation and submission to the App Store and Google Play
  • Source code, documentation and access: all yours

Not included

  • Apple and Google developer fees and third-party services (maps, messaging, payments)
  • Maintenance after launch (contracted separately, month to month)

The proof

What You Can Check

We have not yet published an App Store or Google Play case study on this website. What you can check is the part that weighs most in a business app, the backend. Nexo, our own CRM, projects, invoicing and time-tracking platform, has been in production since July 2023: it is multi-tenant, built with Laravel and React on PostgreSQL, has more than 10 live integrations (Holded, Apollo, Slack and Google APIs), and 90% of its time entries arrive through automated channels such as its API. For Tamarit Beach Resort we built a custom booking engine synced in real time with the resort’s PMS and a 3-step mobile booking flow, with 35% more direct bookings. And we are certified to ISO 27001 and Spain’s National Security Framework (ENS).

  • 2023 Nexo in production since
  • 10+ Live integrations in Nexo
  • 2009 Building software since
  • 5.0 Clutch rating

For the CTO

Summary for the CTO

The technical decisions we make by default.

We design the API before the screens: REST with JSON, token authentication, server-side authorisation and versioning (v1, v2) so apps your users have not updated keep working. Notifications go out from the backend through Firebase Cloud Messaging and APNs, and data that must work offline is stored on the device and synced when the connection returns.

On the app side: automated builds and signing (Codemagic or Fastlane for Flutter, EAS Build for React Native), end-to-end tests (Patrol, Detox or Maestro) and error tracking in production. In React Native, JavaScript fixes can ship as an over-the-air update without a new review; native changes always go through Apple and Google. We work under the controls of our ISO 27001 and ENS certifications: encrypted credentials and personal access for each engineer.

Technologies

  • Flutter
  • Dart
  • React Native
  • TypeScript
  • Expo / EAS
  • PWA
  • Laravel
  • Node.js
  • PostgreSQL
  • Firebase Cloud Messaging
  • APNs
  • Sentry
  • Versioned API, designed before the screens
  • Authorisation on the server, never only in the app
  • Push notifications from the backend (FCM and APNs)
  • Automated builds, signing and tests on every release
  • Production error tracking and planned updates

Risks and how we cover them

The Risks We Avoid

What usually derails an app project.

  1. 01

    Building an app-store app when a PWA was enough (or the other way round)

    Mitigation

    The technology is chosen during discovery, based on what the app must do and who will use it, before quoting.

  2. 02

    An Apple or Google review rejection that delays the launch

    Mitigation

    We check each store’s guidelines during development and build review time into the schedule.

  3. 03

    An iOS or Android update that breaks the app

    Mitigation

    We test new OS versions before they reach your users and keep dependencies up to date.

  4. 04

    Depending on a supplier who holds the code and the accounts

    Mitigation

    The code, documentation and access are yours. If you ever leave, you take everything with you.

Technologies

Technologies

What we use to build apps and their backends.

  • Flutter
  • Dart
  • React Native
  • TypeScript
  • Expo
  • EAS Build
  • PWA
  • Workbox
  • Laravel
  • Node.js
  • PostgreSQL
  • Firebase
  • APNs
  • Sentry
  • Fastlane
  • Codemagic
  • Detox
  • Maestro

FAQ

Mobile App Development FAQs

What people ask us most before commissioning an app.

How much does it cost to build an app?

It depends on the number of screens, the backend and the integrations. For a PWA we publish prices: converting your existing website, €8,000-€15,000; a new PWA with complex offline features, €20,000-€35,000; an enterprise PWA with push, sync and multi-tenancy, €35,000+. For a cross-platform app in Flutter or React Native we do not give a blind figure: after discovery we give you a fixed quote by phase. Excluding VAT.

How long does it take to build an app?

In Flutter or React Native, an MVP with 5 to 8 screens takes 8-10 weeks; a full app with backend, 12-16 weeks; and an enterprise project with integrations, 16-24 weeks. Turning an existing website into a PWA typically takes 2-4 weeks of development. Add the store review time on top.

Native or cross-platform?

For most business apps, cross-platform: one codebase for iOS and Android, lower cost and a single team to maintain it. Native (Swift and Kotlin separately) pays off with very heavy hardware use. When a specific feature requires it, we write that module natively and use it from Flutter or React Native.

Flutter or React Native?

Flutter if you are starting from scratch and want a custom interface that looks identical on both platforms. React Native if your team already works with React, you want to share code with your website, or you value shipping fixes without a store review. Both produce quality apps; the choice depends on your team and your product.

Do I need an app, or is a PWA enough?

A PWA is enough if your audience will not install an app, if content or purchasing is what matters and if you do not need deep phone features (Bluetooth, NFC, background processing). You need an app-store app if you want to be on the App Store and Google Play, if your audience expects to find you there, or if on iOS you need what a PWA cannot offer.

Do you handle publishing on the App Store and Google Play?

Yes: we prepare the listings, screenshots and documentation Apple and Google ask for, build and sign the releases and submit them for review. We build review time into the schedule and, if changes are requested, we deal with them.

Do you build the backend and API as well?

Yes, and it is often half the work. We design the API, authentication, permissions, notifications and integrations with your systems, in Laravel or Node.js. If you already have a backend, the app connects to it and we extend it where needed.

What happens after launch?

Apple and Google release new versions of iOS and Android every year and libraries change. We recommend month-to-month maintenance: updates, error tracking, dependencies kept current and hours for improvements. Maintenance for a custom application starts at €1,200/month; for the app itself it is set after launch.

Do you have published apps I can look at?

We have not yet published an app-store case study on this website. You can see the server side we build for business apps in Nexo, our platform in production since 2023, and on a call we will walk you through how we would approach yours.

Can you take over an app built by another supplier?

Yes. We start by reviewing the code, dependencies, backend and store accounts, and tell you what needs fixing, whether it can be continued or whether it makes more sense to rebuild some parts.

Next step

Tell Us What Your App Needs to Do

A 30-minute video call to understand your idea and your systems. We will tell you whether an app, a PWA or a good website suits you best, and how we would build it.

Talk About My App
  • No commitment
  • Response in 24h
  • Custom proposal
Last updated: October 2026

Let's talk.

Initial technical consultation

AI, security and performance. Diagnosis with phased proposal.

  • NDA available
  • Response <24h
  • Phased proposal

Your first meeting is with a Solutions Architect, not a salesperson.

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