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.








































































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
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.
| Criterion | Web app in the browser | PWA | Cross-platform (React Native) | Native (iOS and Android separately) |
|---|---|---|---|---|
| Installation | None, opened from a URL | 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) | Through the App Store and Google Play | Through the App Store and Google Play |
| Offline operation | No — offline capability only arrives with a service worker, which is the step to a 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) | Yes, with local data storage | Yes, without restriction |
| Push notifications | Not without a service worker — the moment you want push, you are effectively building a PWA | Yes; on iOS only once the app sits on the home screen, available since iOS 16.4 (WebKit, 2023) | Yes, via APNs and FCM like any store app | Yes |
| Hardware access | Camera and microphone through the browser | Camera and microphone yes; no Web Bluetooth, no Background Sync in Safari or iOS Safari (caniuse, 2026) | Camera, biometrics, Bluetooth, background tasks | Everything the platform exposes |
| Discoverability | Google index, links can be shared and linked to | 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) | Store search; the content inside the app stays out of the Google index | Store search; the content inside the app stays out of the Google index |
| Update cycle | Deploy, live for every user immediately | Deploy; installed devices pick up the new version once the service worker has updated | Store review before every update; Apple states it reviews 90% of submissions in under 24 hours on average | Store review per platform, two separate releases |
| Codebases | One | One | One for iOS and Android, web separate | Two, maintained separately |
| Work imposed from outside | No external deadlines, only your own dependency updates | No external deadlines | 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 | Same as cross-platform, but once per platform |
| Our price range | Process pilot €8,000–20,000, full web app €20,000–60,000 | A surcharge for manifest, service worker and offline logic; stays within the range of the respective stage | Web app plus a separate app project, fixed price after discovery | We don't build this — we point you to a specialist team |
| When this form wins | Desk-based use, no offline or push requirement, no need for store presence | Field service, workshop, warehouse: a known user base, login as the entry point, offline and push needed, the store dispensable | Store presence is itself the requirement (procurement, MDM distribution, discoverability), or one of the iOS web gaps blocks the project | Hardware-adjacent parts: wearables, offline mapping, deep operating-system integration |
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.
| Item | Scope | Price range | Timeframe |
|---|---|---|---|
| Process pilot | One process as a web app, sign-in and roles included | €8,000–20,000 | 6–12 weeks to production |
| Full B2B web app | Several processes, interfaces, permission model — optionally as a PWA | €20,000–60,000 | 3–6 months |
| PWA build-out | Manifest, service worker, offline operation, web push | Included in the range of the respective stage | Part of the project plan |
| Cross-platform app with React Native | iOS and Android from one codebase, submission to both stores | Fixed price after discovery | Depends on scope |
| Complex platform, multi-tenancy | Multiple tenants, separated data spaces, a role model per tenant | Fixed price after discovery | Depends on scope |
| Operations setup | Infrastructure, pipelines, monitoring, backups; restore test on request | €5,000–20,000 once | Part of the project |
| Ongoing operation | Hetzner infrastructure plus support from us | €20–50/month hosting, €150–400 for high availability; 2–5 h/month support | Ongoing |
| Further development on retainer | Fixed capacity for new features, maintenance and platform requirements | €4,000–12,000/month | Ongoing |
| Three years of operation | Setup, hosting and support on the open-source stack added up — excluding the build sum and any retainer | €40,000–80,000 | 36 months |
| The alternative: your own senior hire | One senior developer on staff, fully loaded | €145,000–200,000 in the first year | 8–9 productive months |
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
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 teamFAQ
Questions decision-makers ask us before they sign