ServicesMobile app development

Cross-Platform Mobile App Development

Sentia has been building apps in Sydney since 2006. We build cross-platform mobile apps in React Native or Flutter: one codebase for iOS and Android, with native code where a feature needs it.

Tell us about your project

Cross-platform mobile app development in Sydney, used where it fits.

One codebase where it fits.

Most screens, forms and flows work the same on iOS and Android. React Native or Flutter lets us build them once, so both apps ship together and stay in step.

Native where it doesn't.

Bluetooth hardware, heavy background work and demanding graphics can still need native code. We write those parts in Swift and Kotlin and plug them into the shared app.

The platform behind it.

A cross-platform app still needs a back end, an admin tool and two app store releases. We build the whole product with one team, so nothing gets lost in a handoff.

What we build

One codebase, two apps and the platform behind them.

One codebase for iOS and Android.

Taxi booking, with live fare estimates and ride options.

One codebase for iOS and Android.

We build cross-platform apps in React Native or Flutter, sharing the screens, logic and tests across both platforms. You get two store-ready apps from one codebase, released together and kept in step.

See our work
React Native

JavaScript and TypeScript apps that render real native components on iOS and Android.

Flutter

Google's toolkit for one Dart codebase, a strong fit for custom, brand-led interfaces.

Both app stores

We handle App Store and Google Play submission, review and release cycles.

Real-time features

Notifications, live updates and feeds that keep users engaged.

Native code for the parts that need it.

Smart building desk booking, connected to access control and beacon location.

Native code for the parts that need it.

Some features still need native code, such as Bluetooth hardware, background location and camera processing. We write those modules in Swift and Kotlin and connect them to the shared app, so you don't give up the hard parts.

See our work
Bluetooth and BLE

Sensors, proximity detection and asset tracking via Bluetooth Low Energy.

Barcode and QR scanning

Fast, accurate scanning with the phone's camera, built into the app.

Offline-first

Works without signal and syncs automatically when the connection returns.

Native modules

Swift and Kotlin code for what the shared framework can't reach, in the same app.

Multi-platform development, built as one product.

Smartspace (web + mobile — smart building access and management)

Multi-platform development, built as one product.

Your web platform, iOS app and Android app should share the same API, business logic and data. We plan every surface before code is written, so a change made once shows up everywhere.

See our work
APIs and integrations

Back ends and APIs built alongside the app, connected to the systems you already run. Explore API integration

Web platform

Admin tools and web apps that share business logic with the mobile apps.

iPad and tablet

Tablet-optimised layouts for field, clinical and enterprise use.

One team

Web and mobile built together, with no handoffs between separate teams.

Apps that have drifted apart, brought back into line.

Vehicle inspections, field inspector view.

Apps that have drifted apart, brought back into line.

A web app built first and a mobile app added later often end up on different APIs and release cycles. We review what you have, then bring every app onto one shared platform, in stages if that suits.

See our work
Code and architecture review

We start by reviewing the apps, the back end and where they've drifted apart. Explore project rescue

Adding a platform

Add Android to an iOS app, or mobile to a web platform, on the same back end.

Staged rollout

Move one surface at a time, so your users always have a working app.

Native to cross-platform

Where it makes sense, move two native apps onto one shared codebase.

Možemo vam pomoći s...
Mobile Phone App DevelopmentAPI & IntegrationsAndroid App DevelopmentiOS Mobile App Development

Cross-platform or native?

The short answer, before you get a quote.

Cross-platform suits most business apps.

Bookings, marketplaces, field forms and member apps usually work well from one codebase. You build once, test once and release both apps together.

Native suits apps that live on the hardware.

Constant Bluetooth, heavy background work or demanding graphics are usually better built natively, one app per platform in Swift and Kotlin.

Cheaper isn't automatic.

One codebase saves on shared screens, not on design, the back end or two store releases. We'll show you where the savings really are before you commit.

Mixed is often the answer.

Many apps share most of their code and go native for one or two features. We'll recommend what suits your app, not what's easiest for us to build.

Still choosing a platform? See mobile app development.

From one codebase to both app stores

From first conversation to the App Store and Google Play, with the right approach chosen before anything is designed.

Scope and estimate.

We start with what the app needs to do, who it's for and what has to sit behind it. Then we agree the requirements, a roadmap and a detailed estimate.

Choose the approach.

We weigh up the features, devices and budget, then recommend React Native, Flutter, native or a mix, and explain why before anything is designed.

Design and build.

One design for both platforms, adjusted where iOS and Android differ. The app and its back end are built together, and you see working software early.

Both stores and beyond.

We handle App Store and Google Play submission and review. After launch we keep both apps current, through support and maintenance or ongoing development.

Apps we've built across iOS, Android and web

Smart Space

Smart Space

Advanced workplace management with multi-platform solutions

Industrija

Real Estate

Airtasker

Airtasker

Marketplace connecting people to complete everyday tasks and services

Industrija

On-demand Service, Marketplace

Cohabit

Cohabit

Digital platform connecting Lot Owners and Strata Managers

Industrija

Real Estate

RydoStudija slučaja

Rydo

A trusted, real-time rideshare alternative for Australian Taxis

Industrija

On-demand Service, Transport & Logistics

View all mobile projects

Common questions

It means building one app for iOS and Android from a single codebase, using React Native or Flutter. Most of the code is shared, and native code fills any gaps.

Often, but not by half. Design, the back end and two store releases still take work. Send us your brief and we'll give you a detailed estimate, free of charge. For typical ranges, read how much it costs to build an app.

React Native suits teams with JavaScript skills or a React web app. Flutter draws its own interface, which suits custom, brand-led designs. Both are mature, and we'll recommend the one that fits your app.

Not quite. Older hybrid apps run a web page inside a native shell, which is why they felt slow. React Native and Flutter produce real native apps, so ask which kind you've been quoted for.

Yes. Device features like Bluetooth can be written natively and plugged into the shared app. If most of your app depends on them, native is the better choice. See iOS app development and Android app development.

Yes. Sentia can provide a mutual NDA that protects your IP and ours.

There are two options. You can move into support and maintenance, which we can manage, or keep developing while we support the current version. Here's why ongoing support matters.

Yes. We handle React Native and Flutter mobile app development in Sydney for clients across Australia. Sentia has been building apps here since 2006, and our Zagreb team adds delivery capacity.