Web app development — in the browser, as a PWA, or cross-platform with React Native

Most proposals open with the technology. We open with a different question: how should your application reach the people who use it — through the browser's address bar, as an installable progressive web app, or through an app store? That one decision drives effort, build time and running costs more than any framework choice does. A process pilot runs €8,000–20,000 and is in production in 6–12 weeks; a full B2B web app runs €20,000–60,000 over 3–6 months. Whether you should build anything yourself is a separate question, and our custom software page answers it. This page is about the delivery model alone.

What we build: as a web app agency based in Berlin, we write TypeScript across every layer — Next.js on the front end, NestJS on the back end, Postgres through Supabase, Keycloak for sign-in and roles, Sanity for editorial content. If your application needs to keep working offline, send push notifications and sit on a home screen, we build it as a progressive web app. If it needs a place in an app store or access to hardware the browser keeps locked, we use React Native: same language, same team, a second delivery target. Everything runs on EU infrastructure at Hetzner. The source code is yours and the repository is in your company's name from day one.

What we don't build: native iOS apps in Swift or Android apps in Kotlin — our route into the stores is React Native. No consumer apps with a 3D engine, ARKit or game logic. Nothing whose core sits deep in the operating system, which means wearables, offline mapping, continuous background location or geofencing. And nothing under roughly €8,000, because at that size a standard tool usually does the job or a website is enough. If your case falls into one of those, we say so on the first call and point you to what will actually solve it. You talk to Matthias Radscheit, not a sales team: senior-first, no junior staffing.

Logo von 20moments
Logo von Bemer
Logo von Berliner Volksbank
Logo von Clinomic
Logo von Consentmanager
Logo von Deloitte
Logo von DFDC
Logo von einhorn
Logo von Cushman & Wakefield
Logo von in-motion
Logo von myticket
Logo von TES H2

Web app, PWA, cross-platform app: the three delivery models in plain terms

Definition

Web app (web application)
An application that runs in the browser and is reached through a URL: no installation, no app store, one deploy that reaches every device at once. Web application, web app and HTML5 app all mean the same thing. Data, roles and permissions live on the server; the device is little more than a screen. For internal line-of-business tools, dashboards and desk-based processes this is the default form, and it is what most buyers have in mind when they ask for custom web application development.

Definition

Progressive Web App (PWA)
A web app that additionally ships a service worker and a manifest: it can sit on the home screen, opens without browser chrome, keeps working when the connection drops, and can receive push notifications. On iOS and iPadOS, web push has worked since version 16.4, but only for web apps that were added to the home screen first (WebKit, 2023). Since iOS 26, any site added that way opens as a web app by default, with no installability criteria left to meet (WebKit, September 2025). A PWA can be published to Google Play through a Trusted Web Activity and to the Microsoft Store as an MSIX package. The Apple App Store has no such route.

Definition

Cross-platform app with React Native
An app built from a single TypeScript codebase for iOS and Android that ships as a real app in both stores, with access to camera, biometrics, Bluetooth and background tasks. React Native has run on the new architecture by default since version 0.76 in October 2024, and since 0.84 in February 2026 with Hermes V1 as the default engine; the current release is 0.86 from June 2026. Microsoft Office and Outlook, Amazon Shopping and Kindle, and the Shopify apps all run on it (React Native Showcase). The maturity question is settled. The only one still open is whether your project needs store presence at all.

A word on the vocabulary this market keeps muddying: web app development, web application development and custom web application development all describe the same thing, and hybrid app, cross platform app development and React Native app do too. It is the additions — installable, offline-capable, findable in a store — that turn a web app into a PWA or a cross-platform app. How much the iOS limits of a PWA actually cost you depends on who your users are: in Germany, for example, iOS accounted for 39.12% of mobile operating systems in June 2026 and Android for 60.86% (StatCounter, 2026), and your own analytics will tell you where your user base sits. If the open question is still whether to build at all, custom software development answers it, alongside the decision guide website, web app or portal. Why we run one language across every layer is on TypeScript agency; what the infrastructure costs month to month is broken down on Supabase in production.

Security & compliance

Your customers trust you with sensitive data. We take that responsibility seriously.

Whether it's your data protection officer, your IT security team or a major customer's procurement: when security questions come up, you have solid answers. We build in data protection and security from day one and follow the principles of the Twelve-Factor App. That makes approvals and audits easier and gives you the technical foundation to meet requirements under GDPR, ISO 27001 or HIPAA.

Frameworks whose technical requirements we implement in our projects

  • GDPR
  • ISO 27001
  • HIPAA
  • NIS2
Discuss your requirements in an intro call

Web app, PWA, React Native or native: the decision table

This table is the core of the page. None of the four forms is better than the others in the abstract — they differ in what they are allowed to do and in what they cost. If you are in a hurry, read the last row first: it says when each form wins. Everything above it is the reasoning.

Installation

Web app in the browser
None, opened from a URL
PWA
Share → Add to Home Screen; since iOS 26 every site added that way opens as a web app (WebKit, 2025), but there is still no automatic install prompt there, because beforeinstallprompt is not a standard (MDN)
Cross-platform (React Native)
Through the App Store and Google Play
Native (iOS and Android separately)
Through the App Store and Google Play

Offline operation

Web app in the browser
No — offline capability only arrives with a service worker, which is the step to a PWA
PWA
Yes, via a service worker; on iOS 17+ an installed web app gets the same storage quota as the browser, up to 60% of device storage per origin (WebKit, 2023)
Cross-platform (React Native)
Yes, with local data storage
Native (iOS and Android separately)
Yes, without restriction

Push notifications

Web app in the browser
Not without a service worker — the moment you want push, you are effectively building a PWA
PWA
Yes; on iOS only once the app sits on the home screen, available since iOS 16.4 (WebKit, 2023)
Cross-platform (React Native)
Yes, via APNs and FCM like any store app
Native (iOS and Android separately)
Yes

Hardware access

Web app in the browser
Camera and microphone through the browser
PWA
Camera and microphone yes; no Web Bluetooth, no Background Sync in Safari or iOS Safari (caniuse, 2026)
Cross-platform (React Native)
Camera, biometrics, Bluetooth, background tasks
Native (iOS and Android separately)
Everything the platform exposes

Discoverability

Web app in the browser
Google index, links can be shared and linked to
PWA
Google index; plus publication to Google Play through a Trusted Web Activity and to the Microsoft Store as MSIX, but not to the Apple App Store (App Review Guideline 4.2)
Cross-platform (React Native)
Store search; the content inside the app stays out of the Google index
Native (iOS and Android separately)
Store search; the content inside the app stays out of the Google index

Update cycle

Web app in the browser
Deploy, live for every user immediately
PWA
Deploy; installed devices pick up the new version once the service worker has updated
Cross-platform (React Native)
Store review before every update; Apple states it reviews 90% of submissions in under 24 hours on average
Native (iOS and Android separately)
Store review per platform, two separate releases

Codebases

Web app in the browser
One
PWA
One
Cross-platform (React Native)
One for iOS and Android, web separate
Native (iOS and Android separately)
Two, maintained separately

Work imposed from outside

Web app in the browser
No external deadlines, only your own dependency updates
PWA
No external deadlines
Cross-platform (React Native)
Recurring and externally scheduled: from 31 Aug 2026 Google Play requires new apps and updates to target Android 16 (API 36), with an extension to 1 Nov 2026 available on request; since 28 Apr 2026 Apple requires uploads built with Xcode 26 and the iOS 26 SDK
Native (iOS and Android separately)
Same as cross-platform, but once per platform

Our price range

Web app in the browser
Process pilot €8,000–20,000, full web app €20,000–60,000
PWA
A surcharge for manifest, service worker and offline logic; stays within the range of the respective stage
Cross-platform (React Native)
Web app plus a separate app project, fixed price after discovery
Native (iOS and Android separately)
We don't build this — we point you to a specialist team

When this form wins

Web app in the browser
Desk-based use, no offline or push requirement, no need for store presence
PWA
Field service, workshop, warehouse: a known user base, login as the entry point, offline and push needed, the store dispensable
Cross-platform (React Native)
Store presence is itself the requirement (procurement, MDM distribution, discoverability), or one of the iOS web gaps blocks the project
Native (iOS and Android separately)
Hardware-adjacent parts: wearables, offline mapping, deep operating-system integration

Four signposts so you don't end up on the wrong page. If your customers log in — order status, documents, self-service — your project belongs on customer portal development. If a legacy system is holding you back and the new thing should grow beside it step by step, read software modernization. If you need visibility and leads rather than a login, the B2B website is the right place. And if it is still open whether to build or to buy, custom software development and when custom software pays off settle that. When you should not buy this from us: consumer apps with a 3D engine, ARKit or game logic; projects whose core sits deep in the operating system, meaning wearables, offline mapping or continuous background location, because native code is the right answer there and we are not the right team; budgets under roughly €8,000, because a standard tool or a website usually carries those; a one-to-one rebuild of an existing SaaS product; and any plan that has twenty developers on it by month two, because we work senior-first in small teams. Even Shopify, which runs its apps entirely on React Native, states it plainly: "100% React Native should be an anti-goal" (Shopify Engineering, January 2025). For hardware-adjacent parts, native code stays the right answer — and we say so instead of selling you something else.

If you are building a new product and it is still open whether customers will use and pay for it, start with an MVP: scope, pricing and process are on our MVP development page.

Three routes into production

We almost always start with the smallest slice that covers one real process end to end. We deliberately fix the delivery model late, usually at the close of discovery, once it is clear how and where the thing will be used. What it costs to reverse that order is in the price table further down.

Process pilot as a web app

from €8,000

in production in 6–12 weeks

One bounded process goes into production in the browser, with sign-in and roles.

  • Discovery

    Ending in a reasoned decision on the delivery model.

  • Next.js, NestJS, Supabase, Keycloak

    Postgres as the database, Keycloak for sign-in and roles.

  • Hosted at Hetzner in the EU

    The repository is in your name.

  • Measured usage

    You decide on real usage instead of assumed requirements.

Full web app or PWA

from €20,000

built in 3–6 months

Several processes with a permission model and interfaces, installable and usable offline if you need it.

  • PWA with an offline queue

    Manifest, service worker and conflict resolution when syncing.

  • Web push notifications

    On iOS only after installation on the home screen.

  • ERP, DATEV and CRM connections

    Or your legacy system, through documented interfaces.

  • Role and permission model

    Plus load testing and handover documentation.

  • Multi-tenant platforms

    Quoted at a fixed price after discovery.

Cross-platform app with React Native

For when you need to be in the app stores or the browser will not expose the hardware.

  • One codebase for iOS and Android

    In TypeScript: you maintain one app instead of two.

  • Publishing to the stores

    App Store and Google Play, developer accounts in your name.

  • Camera, biometrics, Bluetooth

    Plus background sync and distribution via MDM.

  • Platform requirements kept current

    You don't have to track Apple's and Google's deadlines yourself.

  • Fixed price after discovery

    Its own project alongside the web app, then operation on a retainer.

All prices exclude VAT, as of October 2026.

What a web app costs — and what it costs afterwards

Almost nobody in this field quotes numbers, and nobody quotes what running the thing costs. So here is both: the build, and the three years after it. The ranges come from our own projects and are explicitly not a market study. How the running costs break down in detail — infrastructure, monitoring, backups, the hours per month — is set out on our Supabase page and in our article on custom software development costs.

Process pilot

Scope
One process as a web app, sign-in and roles included
Price range
€8,000–20,000
Timeframe
6–12 weeks to production

Full B2B web app

Scope
Several processes, interfaces, permission model — optionally as a PWA
Price range
€20,000–60,000
Timeframe
3–6 months

PWA build-out

Scope
Manifest, service worker, offline operation, web push
Price range
Included in the range of the respective stage
Timeframe
Part of the project plan

Cross-platform app with React Native

Scope
iOS and Android from one codebase, submission to both stores
Price range
Fixed price after discovery
Timeframe
Depends on scope

Complex platform, multi-tenancy

Scope
Multiple tenants, separated data spaces, a role model per tenant
Price range
Fixed price after discovery
Timeframe
Depends on scope

Operations setup

Scope
Infrastructure, pipelines, monitoring, backups; restore test on request
Price range
€5,000–20,000 once
Timeframe
Part of the project

Ongoing operation

Scope
Hetzner infrastructure plus support from us
Price range
€20–50/month hosting, €150–400 for high availability; 2–5 h/month support
Timeframe
Ongoing

Further development on retainer

Scope
Fixed capacity for new features, maintenance and platform requirements
Price range
€4,000–12,000/month
Timeframe
Ongoing

Three years of operation

Scope
Setup, hosting and support on the open-source stack added up — excluding the build sum and any retainer
Price range
€40,000–80,000
Timeframe
36 months

The alternative: your own senior hire

Scope
One senior developer on staff, fully loaded
Price range
€145,000–200,000 in the first year
Timeframe
8–9 productive months
As of 30 July 2026
The ranges reflect our own experience and do not replace a quote. They assume senior staffing with no junior pass-through, and they assume that someone on your side decides and answers within a few days. The price becomes binding after discovery.

Who works on your project

Our senior team in Berlin, from the first draft to production. You talk directly to the people who write your code.

Meet the team

FAQ

Questions decision-makers ask us before they sign

A process pilot runs €8,000–20,000 and is in production in 6–12 weeks. A full B2B web app with several processes, interfaces and a permission model runs €20,000–60,000 over 3–6 months. For multi-tenant platforms we quote a fixed price after discovery. Custom web application development at this level is priced for senior staffing throughout, with no junior pass-through. Running the thing is costed separately: €5,000–20,000 once for setup, then €20–50 per month for hosting, €150–400 for a high-availability setup, plus 2–5 hours of support per month. Over three years that operating share adds up to €40,000–80,000 — the build sum sits in front of it, not inside it.

By where the work happens, not by the technology. If people work at a desk and there is neither an offline nor a push requirement, a web app in the browser is enough. If the work happens in the field, in a workshop or in a warehouse where the connection drops, it becomes a PWA. Only when store presence is itself the requirement, or the browser will not expose the hardware you need, does React Native pay for itself. We make that call at the end of discovery, not before it. Getting it wrong is the most expensive mistake in the whole project.

Three things, and we name them before any contract is signed. First, there is no automatic install prompt: the user has to add the page to the home screen through the share sheet, because beforeinstallprompt is not a standard and does not exist in Safari (MDN). Second, push notifications only work after exactly that step; they have been available since iOS 16.4 (WebKit, 2023). Third, Background Sync and Web Bluetooth are missing in Safari and iOS Safari across the board (caniuse, as of 2026). If your project rests on any one of those, we do not build a PWA — we build a React Native app.

No. Apple announced it in February 2024 and reversed the decision before iOS 17.4 shipped: "we will continue to offer the existing Home Screen web apps capability in the EU" (Apple Developer Support, 2024). The opposite claim still circulates in agency blogs. Since iOS 26, every website added to the home screen even opens as a web app by default, with no installability requirements attached (WebKit, September 2025). A different sentence does stay true: on the iPhone, WebKit alone still decides what a web app is allowed to do.

Into Google Play, yes, through a Trusted Web Activity with a manifest, HTTPS and Digital Asset Links. Into the Microsoft Store as well, as an MSIX package. Into the Apple App Store, no: App Review Guideline 4.2 requires functionality beyond a repackaged website. If your application has to be in Apple's store — because that is where buying, distribution or searching happens — the route goes through React Native. The Apple Developer Program costs 99 USD per year for that (Apple, 2026).

That question is answered. The new architecture has been the default since version 0.76 in October 2024, the old bridge was removed in 0.82, Hermes V1 became the default engine in 0.84, and the current release is 0.86 from June 2026. Microsoft Office, Outlook and Teams, Amazon Shopping and Kindle, and the Shopify apps all run on it (React Native Showcase). After its full migration, Shopify reports more than 99.9% crash-free sessions and screen load times under 500 milliseconds at the 75th percentile (Shopify Engineering, January 2025). If you are picking a React Native development company this year, maturity is not the thing to interrogate.

Because one language across every layer removes the translation losses. TypeScript on the front end with Next.js, on the back end with NestJS, in the app with React Native, with Postgres through Supabase and Keycloak for sign-in and roles. The same people can touch any layer without a handover to another team. Agencies that offer React and Angular and Java and Python at the same time have simply not made this decision. They push it into your project instead.

The source code is yours, and the repository is in your company's name from the start. We build on open-source components with no licence fees, running on EU infrastructure at Hetzner. Store accounts for a React Native app are opened under your company, not ours. A documented handover path to your own IT or to another team is part of the delivery. Switching providers must never fail because knowledge sits inside an agency.

First, fixing the delivery model too early — usually on "app" — before anyone has looked at where the work actually happens. Second, adding the offline requirement late: retrofitting local storage, a queue and conflict resolution costs a multiple of planning them in. Third, demanding the app store when nobody needs it, which buys you a review before every update plus the platform deadlines Apple and Google set for you. Fourth, bolting on multi-tenancy instead of designing the data model for it from the first line.

When you need a consumer app with a 3D engine, ARKit or game logic. When the core of your project sits deep in the operating system: wearables, offline mapping, continuous background location or geofencing. When your budget is under roughly €8,000, because a standard tool or a website usually carries that. When an existing SaaS product is to be rebuilt one to one. And when you expect twenty developers by month two — we work senior-first in small teams and scale through scope, not headcount. In those cases another web app development company is the right call, and we will say so in the first conversation.

Open for select projects

Let's talk about your project

Book a no-obligation call, send us an email, or use the form – we'd love to hear from you.

150+
Completed projects
15
Years of experience
7
Senior‑level team members