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SERVICE

Mobile App Modernization

Bring Your Existing App Up to Today's Standard Without Starting Over.

We modernize ageing iOS and Android apps by upgrading outdated codebases, refreshing the user experience, and moving to current frameworks and architectures so your app stays fast, secure, store-compliant, and ready for new features.

Talk to an expertSee our work
  • Codebase audit & modernization roadmap
  • Swift, Kotlin, SwiftUI & Jetpack Compose migration
  • UI/UX refresh for current platform standards
  • Performance, security & store-compliance upgrades
  • Phased rollout with zero data loss
Mobile App Modernization

Full Audit

Code, Architecture, UX and Performance Review

OVERVIEW

Mobile App Modernization built around how your business works.

Our goal

Extend the life and value of your existing mobile app with a modern, maintainable foundation.

Mobile apps age quickly. OS updates deprecate APIs, store policies change, and older codebases become slow and expensive to extend. At Creuto, we modernize existing apps incrementally, keeping what works and rebuilding what holds the product back.

An app built a few years ago can quickly fall behind: crashes on new OS versions, outdated UI, store compliance warnings, and features that take months to ship.

We start with a technical and UX audit of your current app, identifying what to keep, what to refactor, and what to rebuild.

Modernization can mean migrating Objective-C to Swift, Java to Kotlin, adopting SwiftUI or Jetpack Compose, or consolidating separate apps into React Native or Flutter.

We modernize in phases, releasing improvements continuously so your users keep a working app and your data stays intact throughout.

The result is an app that is faster, easier to maintain, compliant with current store requirements, and ready for the next stage of your product roadmap.

What every engagement includes

  • Codebase audit & modernization roadmap
  • Swift, Kotlin, SwiftUI & Jetpack Compose migration
  • UI/UX refresh for current platform standards
  • Performance, security & store-compliance upgrades
  • Phased rollout with zero data loss
WHAT WE DELIVER

Our Mobile App Modernization Services

Upgrade, refactor, and redesign your existing mobile app without starting from scratch.

/01

App Audit & Modernization Roadmap

A detailed review of code quality, architecture, dependencies, UX, and performance, with a prioritised upgrade plan.

Discuss this
/02

Native Language Migration

Migrating Objective-C to Swift and Java to Kotlin for safer, faster, and easier-to-maintain code.

Discuss this
/03

Modern UI Framework Adoption

Moving screens to SwiftUI and Jetpack Compose incrementally, alongside your existing views.

Discuss this
/04

Cross-Platform Consolidation

Consolidating separate iOS and Android codebases into React Native or Flutter where it makes sense.

Discuss this
/05

UI/UX Redesign

Refreshing outdated interfaces to current platform guidelines, accessibility standards, and user expectations.

Discuss this
/06

Performance Optimisation

Reducing launch time, app size, memory use, and crashes on modern devices and OS versions.

Discuss this
/07

Backend & API Modernization

Replacing legacy backends and APIs with scalable, secure services that support new features.

Discuss this
/08

OS & Store Compliance Updates

Keeping your app compatible with the latest iOS and Android releases and App Store and Google Play policies.

Discuss this
HOW WE WORK

Our Mobile App Modernization process.

Transparent, sprint-based and built around decisions you can see. You know what ships, when, and why at every step.

Start Your Project
  1. 01

    App & Codebase Audit

    Reviewing architecture, code quality, dependencies, analytics, and user feedback to find what's holding the app back.

  2. 02

    Modernization Strategy

    Deciding what to refactor, rebuild, or replace, and defining a phased roadmap with clear milestones.

  3. 03

    UX Refresh & Design

    Redesigning key flows and screens to current platform standards while keeping familiar patterns for existing users.

  4. 04

    Incremental Refactoring & Migration

    Modernizing the codebase module by module, with automated tests protecting existing behaviour.

  5. 05

    Testing & Phased Rollout

    Regression testing on real devices and staged store releases to minimise risk for existing users.

  6. 06

    Ongoing Support & Evolution

    Keeping the app current with new OS releases, dependency updates, and feature development.

RESULTS

What Every Engagement Covers

A structured path from an ageing app to a modern, maintainable product.

Full Audit

Code, Architecture, UX and Performance Review

Phased

Incremental Releases Without Downtime

Data-Safe

User Data and Accounts Preserved Throughout

Store-Ready

Current iOS, Android and Store Policy Compliance

WHY CREUTO

Why Choose Creuto for Mobile App Modernization?

The reasons clients give when they recommend us, not the ones we would pick ourselves.

Bring Your Existing App Up to Today's Standard Without Starting Over.

Our promise on every Mobile App Modernization engagement.

0+

Products delivered

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Years of engineering

0%

Client satisfaction

Start a conversation
  1. /01

    Modernize, Don't Rewrite by Default

    We keep what works and only rebuild what's holding the product back, saving time and budget.

  2. /02

    Native and Cross-Platform Expertise

    Experienced with Swift, Kotlin, SwiftUI, Jetpack Compose, React Native, and Flutter.

  3. /03

    No Disruption for Your Users

    Phased releases and careful data migration keep your app live and your users' data intact.

  4. /04

    Design and Engineering Together

    UX refresh and code modernization planned together, so the app looks and works like a modern product.

  5. /05

    Tested at Every Step

    Automated and real-device testing protects existing features while the codebase changes underneath.

  6. /06

    Long-Term Partnership

    Ongoing updates for new OS versions, dependencies, and features after modernization is complete.

INDUSTRIES

Industries we deliver Mobile App Modernization for.

Sector pages with the solutions, compliance, integrations and FAQs specific to each market.

Healthcare

Patient apps, telehealth, EHR integrations and hospital systems built around clinical workflows.

Banking & Financial Services

Banking, payments, lending, wealth, insurance and digital asset platforms built for security and compliance.

eCommerce & Retail

Online stores, mobile commerce, marketplaces and omnichannel retail systems built to convert.

Logistics & Supply Chain

Fleet, warehouse, last-mile and supply chain visibility platforms for logistics operators.

Education & EdTech

LMS, online courses, virtual classrooms and school administration platforms.

Real Estate & PropTech

Listing portals, agent CRMs, property management and investment platforms.

Travel & Hospitality

Booking engines, travel marketplaces, itinerary apps and guest experience platforms.

Restaurants & Food Service

Ordering, reservations, kitchen operations, loyalty and delivery for restaurants and chains.

TECHNOLOGY STACK

Technology stack for Mobile App Modernization at Creuto.

Chosen per project for longevity, hiring depth and fit with your existing systems, never by fashion.

/01Mobile

  • Swift
  • SwiftUI
  • Kotlin
  • Jetpack Compose
  • Flutter
  • React Native

/02Web and backend

  • React
  • Next.js
  • TypeScript
  • Node.js
  • NestJS
  • Python
  • Django
  • .NET
  • Java

/03Data

  • PostgreSQL
  • MongoDB
  • Redis
  • Elasticsearch
  • BigQuery
  • Snowflake

/04AI and analytics

  • Claude
  • OpenAI
  • LangChain
  • PyTorch
  • TensorFlow
  • pgvector
  • Pinecone

/05APIs and integrations

  • REST
  • GraphQL
  • gRPC
  • Webhooks
  • Kafka
  • RabbitMQ
  • Stripe

/06Cloud and DevOps

  • AWS
  • Azure
  • Google Cloud
  • Docker
  • Kubernetes
  • Terraform
  • GitHub Actions

/07Security and identity

  • OAuth 2.0
  • OpenID Connect
  • SAML
  • Auth0
  • Keycloak
  • AWS KMS
  • Vault

/08Quality and observability

  • Jest
  • Playwright
  • Cypress
  • pytest
  • Sentry
  • Grafana
  • Datadog
TESTIMONIALS

Don't take our word for it.

Founders and product leaders on what it is like to build with Creuto.

“We always felt supported and in sync with their team.”

Creuto's work streamlined the client's processes, improved batch traceability, and made production planning more efficient, dropping manual paperwork by 80%. Moreover, the team managed the project smoothly, was timely, and communicated clearly. Overall, Creuto's openness was impressive.

KV

Karan Verma

Project Manager, Galgoties

Read on Clutch

More client voices

/01 of 06

on Clutch
FAQ

Frequently Asked Questions

Straight answers about Mobile App Modernization projects. If yours is not here, ask us directly.

Ask our team

It depends on the state of the codebase and your goals. Our audit gives you a clear recommendation, and in most cases phased modernization delivers results faster and with less risk than a full rewrite.

No. We modernize in phases with staged store releases and careful data migration, so the app stays available and user data is preserved.

Yes. We start with a thorough audit to understand the existing code before making any changes.

A focused upgrade can take 4–8 weeks, while a full migration of a larger app typically runs over several months in phases.

Yes. Where it suits your product, we can consolidate native apps into React Native or Flutter while preserving the native experience your users expect.

LET'S BUILD

Give Your Mobile App a Second Life.

A modern codebase, a refreshed experience, and a clear upgrade path, delivered without disrupting your users.

Book a callTalk to Our Mobile Modernization Team
  • Reply within one business day
  • NDA on request
  • Senior engineers only
  • Fixed scope, no surprises