iOS · Android · React Native · Flutter
Mobile App Development

Mobile App Development UK — iOS, Android, React Native & Flutter

Tackxel is a UK React Native development agency that ships production iOS and Android apps for founders and product teams. Flutter, native Swift, and Kotlin where they're the right tool. 11+ shipped apps including LuxeLocker, YallaGrub, Sukuk, Guardspur, and WearOpal.

Senior engineers, App Store + Play Store-ready pipelines, and a delivery cadence that gets your mobile app in users' hands — not stuck in QA.

Free 30-minute scoping call with a senior mobile engineer. NDA on request.
Mobile app development for iOS and Android
Who this is for

Three teams we ship for again and again

We tune scope, team mix, and process to where you actually are — not a generic playbook.

Early-stage startup

MVP from zero in 10–14 weeks.

You need a credible v1 in users' hands to validate the thesis, raise the next round, or both. We start with discovery, ship a focused MVP, and instrument it so the next decision is evidence-based — not vibes.

  • Lean scope defined alongside founders, not against them.
  • Production-grade from day one — no throwaway prototypes.
  • Analytics and crash reporting wired in before launch.
Scaleup adding mobile

Native mobile that matches your web product.

You have a working web product and a customer base asking for mobile. We add iOS and Android without splintering your team, sharing your API contracts, design system, and release cadence.

  • Reuses your existing API, auth, and analytics infrastructure.
  • Design-system-aware — your brand survives the platform jump.
  • Embeds with your engineering team, not around it.
Enterprise modernising legacy

Replace the app your users complain about.

Your current app is on an unmaintained framework, leaks crashes, or fails App Store review. We rebuild on a modern stack with feature parity first, then expand — without losing the institutional knowledge that lived in the old codebase.

  • Strangler-pattern migration: ship in slices, not big bangs.
  • Backwards-compatible APIs so backend changes lag the rewrite.
  • Compliance-aware (HIPAA, SOC 2, GDPR) when your data demands it.
What you get

Concrete deliverables, not slide-deck promises

Every engagement ships these — they're not upsells. If something here doesn't apply to your scope, the scoping call is where we say so honestly.

iOS + Android apps

Native (Swift / Kotlin) or cross-platform (React Native / Flutter) — chosen against your team, budget, and platform-feature needs. Not religion.

App Store + Play Store submission

We handle the whole submission gauntlet — provisioning, certificates, review responses, phased rollouts, and store listing copy and assets.

CI/CD pipeline

Fastlane or EAS pipelines for automated builds, signing, TestFlight / internal track distribution, and one-tap production releases.

Analytics + crash reporting

Product analytics (Amplitude / PostHog / Mixpanel), crash reporting (Sentry / Crashlytics), and dashboards your team can read on day one.

Design system + handover docs

Figma component library, design tokens, engineering walkthrough, and runbooks — so the next change doesn't require us in the room.

90-day post-launch support

Bug fixes, store-review pushback, and an SLA on critical issues. We don't ship and disappear — we operate alongside you through the first quarter.

How we deliver

Discover. Design. Build. Ship.

The same four-phase process we run for every engagement — adapted to mobile constraints. Predictable cadence, written deliverables at each phase, no theatre.

01
Week 1–2

Discover

Stakeholder workshops, technical discovery, and a risk-prioritized backlog. We surface unknowns before they become surprises.

  • Technical scoping document
  • Risk register
  • Delivery roadmap
02
Week 2–4

Design

Architecture decisions, system diagrams, and UX prototypes. Engineering and design move in lockstep from the start.

  • System architecture
  • Interactive Figma prototype
  • Data model & API spec
03
Ongoing

Build

Senior engineers ship in two-week sprints with shared dashboards. Daily standups, weekly demos, written status reports.

  • Production-grade code
  • CI/CD pipelines
  • Test coverage > 80%
04
Launch + ongoing

Ship

Phased rollouts with feature flags, observability, and on-call rotation. We do not hand over and disappear — we operate alongside you.

  • Monitoring & alerting
  • Runbooks
  • Incident response SLAs
Tech stack

We pick the stack for the job, not the resume

Cross-platform when speed and team economics matter. Native when the platform features or performance demand it. The scoping call is where we make the call together.

React Native

When you want one codebase, fast iteration, and JS/TS team fluency to carry across web and mobile.

Flutter

When you want pixel-perfect custom UI, strong performance, and don't mind investing in Dart for the win.

Swift

When iOS is the priority surface and you need the latest platform features — widgets, Live Activities, ARKit, on-device ML.

Kotlin

When Android is non-negotiable — Material 3, Jetpack Compose, and full access to background and hardware APIs.

Case study · Healthcare
Vital Health Networks

A patient platform serving 7M+ users across iOS and Android.

We rebuilt Vital Health's patient-facing mobile app from a brittle hybrid stack onto React Native — feature parity in 14 weeks, then expanded with telehealth, prescription refills, and HIPAA-compliant messaging. Senior engineers operated alongside the in-house team, with App Store releases moving from quarterly to fortnightly.

7M+
Patients served on the platform
14 wks
From kickoff to feature parity
6×
Faster store-release cadence
Talk about a similar build
Marcus Williams

"We have worked with five development partners over the years. Tackxel is the only one we trust with our patient-facing systems. HIPAA-grade discipline without the enterprise consultancy markup."

Chief Technology Officer, Vital Health Networks
Related case studies
Related insights
FAQ

Frequently asked questions

Quick answers to the questions buyers ask before a discovery call.

Should I build my mobile app in React Native, Flutter, or native?+
It depends on the product. React Native is our default for most builds — it shares code with your TypeScript web stack, ships iOS and Android with a small team, and is mature and well-supported. Flutter is right for design-led products with custom animations. Native Swift + Kotlin is right when you need deep platform features (advanced camera/AR, HealthKit, on-device ML) or the platform-native feel is the moat. We give a straight recommendation based on your product, not a framework preference.
How long does it take to build a mobile app?+
A focused MVP typically goes to the App Store in 10–14 weeks. A more complex app with multiple roles, integrations, and polish is 4–6 months. We can usually have your first internal build (TestFlight / Play internal track) running within 2–3 weeks so progress is visible early.
How much does mobile app development cost in the UK?+
Rough ranges: a focused mobile MVP is £35k–£80k; a full production app with multiple workflows, integrations, and design polish is £80k–£200k; cross-platform builds (iOS + Android via React Native or Flutter) are usually ~30–50% cheaper than separate native codebases. We scope honestly and give a written range before any commitment.
Do you publish apps to the App Store and Play Store?+
Yes. We handle the full release pipeline — provisioning, signing, App Store Connect setup, Google Play Console, listings, screenshots, review responses, and the first round of post-submission fixes. We can also publish under your developer accounts or set them up if you don't have them yet.
Can you take over an existing mobile app codebase?+
Yes — we regularly inherit codebases, including React Native, Flutter, native, and older Cordova/Ionic apps. We start with a short technical audit (codebase, architecture, build pipeline, security) and a written assessment. From there we can stabilise, modernise, or rebuild — whichever the audit shows is the right call.
Do you provide ongoing maintenance after launch?+
Yes. Post-launch we typically offer a 90-day stabilisation period included in the build, then a small monthly retainer for OS updates, library upgrades, store policy changes, bug fixes, and small enhancements. Larger feature work is scoped separately. You can also bring the maintenance in-house — we hand over cleanly.
What's included in your mobile app development service?+
Discovery, product design, iOS + Android engineering, store submission, analytics and crash reporting wired in from day one, CI/CD pipelines, technical documentation, and a 90-day post-launch period. We can also lead the back end (Node / Next.js APIs), AI features, or IoT/BLE integrations when the product needs them.
Ready when you are

Two ways to start — pick the one that fits your week.

Discovery calls are for figuring out if we're the right fit. Estimates are for when you already know the shape of what you want to build and need numbers to bring to the table.

Book a discovery callGet a delivery estimate