Mobile App Development Company

Mobile App Development Services

iOS, Android and Flutter apps, with the backend to match

SyncScrum designs and builds mobile apps for both stores, native or cross-platform with Flutter, and the API, authentication, notifications, payments and admin tooling behind them. One team is accountable for the app, the backend and the release.

Discuss your app Native vs cross-platform

iOS

Android

One backend

APIAuthPushPaymentsAnalytics

Flutter, native iOS and Android
Backend, APIs and admin included
App Store and Google Play release handled

Native or cross-platform

The decision most teams get wrong in one direction or the other. This is how we make it.

Comparison of cross-platform Flutter and native iOS and Android development
Consideration	Flutter (cross-platform)	Native iOS + Android
Codebases	One, for both stores	Two, one per platform
Performance	Native-compiled; suitable for almost all business and consumer apps	Best possible; needed for heavy graphics or hardware-bound apps
Platform features	Full access through plugins; the newest OS APIs can lag slightly	Immediate access to every platform API
Team and cost	Smaller team, faster to ship and maintain	Two skill sets, more coordination
Best for	Most apps: marketplaces, field tools, customer apps, internal apps	AR, advanced camera or sensor use, deep OS integration

What is included

The whole product, not just the app binary

Mobile UX and UI

Mobile-first flows, platform conventions respected, every state designed.

The app

Flutter or native, with automated tests, crash reporting and performance budgets.

Backend and API

Node.js or Python services, PostgreSQL or Supabase, designed for mobile latency and offline sync.

Authentication and payments

Sign-in options, biometrics where useful, in-app purchases or Stripe.

Push, analytics and admin

Notifications, event tracking and the admin tools your team uses to run the app.

Store release

Accounts, signing, listings, review, staged rollouts and updates.

What we measure before an app ships

Startup time
Cold and warm start measured on mid-range devices, not just the newest flagship.
Scrolling and lists
Long lists, images and animations kept smooth with profiling, not guesswork.
Offline and poor networks
What the app does with no signal is designed and tested.
Battery and data
Background work, polling and media sized for real usage.
Device coverage
Screen sizes, OS versions and accessibility settings tested on real devices.
Crash-free sessions
Crash reporting wired in before beta, watched after launch.

How it runs

From scope to the app stores

Step 1: Scope and platform decision
Features, platforms, backend needs, integrations and the release plan, decided with you.
Scope and platform choice
Step 2: Design
Mobile-first flows and screens, prototyped on a device before build.
Clickable prototype
Step 3: Build
App and backend in parallel, with beta builds to your phone every sprint.
Beta builds
Step 4: Test and harden
Automated and device testing, performance and offline checks, crash reporting.
Release candidate
Step 5: Release
Store listings, review, staged rollout and monitoring.
Live in both stores
Step 6: Iterate
Analytics, reviews and OS changes drive the next releases.
Ongoing updates

Need the design first? See UI/UX design.

A client on their mobile app

Published feedback from a client whose mobile app SyncScrum developed and supports.

“I am thrilled with Sync Scrum! They developed our mobile app flawlessly, delivering high-quality work on time. Their expertise and dedication ensure issues are resolved promptly every time.”

Eric Sierra

CEO (The Real Fitness)

Mobile app development questions, answered

Native or cross-platform: which should we choose?

Cross-platform with Flutter suits most business and consumer apps: one codebase, native performance, both stores. Native iOS and Android make sense when the app depends heavily on platform-specific hardware, background behaviour or the latest OS features. We recommend per project, and the comparison on this page is the one we use.

Do you build the backend as well?

Yes. Most mobile apps are thin clients over an API. We build the backend, authentication, push notifications, payments and the admin tools, so there is one team accountable for the whole product.

Do you handle App Store and Google Play release?

Yes: developer accounts, certificates and signing, store listings, review guidelines, staged rollouts and the updates after launch.

Can you add a mobile app to an existing web product?

Yes. We reuse the existing API where possible, design the app against the same design system, and add what mobile needs: offline behaviour, push notifications and device features.

How do you test mobile apps?

Automated tests for logic and UI, device testing across screen sizes and OS versions, beta distribution through TestFlight and Play internal testing, and crash reporting in production.

What about performance and offline use?

Startup time, list performance, image handling and battery use are measured, not assumed. Offline-first data with sync is designed in when the app is used in the field or on poor connections.

How much does a mobile app cost?

It depends on the features, platforms, backend and integrations. After a scoping conversation we provide a phased estimate with the assumptions written down.