Lower risk than a full rewrite
Use a phased modernization—refactoring, incremental migration or targeted rebuilds of the worst-performing parts—instead of a single high-risk relaunch.
Mobile App Development
App Modernisation
Modernise an outdated iOS or Android app without a risky, ground-up rewrite—phased upgrades to the tech stack, performance and design that protect your App Store rating and existing users while you fix what's actually broken.
Improve performance, usability and maintainability.
- Phased
- modernization
- Zero
- big-bang rewrites
- Ratings &
- performance protected
01
Quick answer
What is mobile app modernization?
Mobile app modernization updates an existing iOS or Android app's code, architecture, UI or platform compatibility so it stays fast, secure and maintainable—without necessarily rebuilding it from scratch. Integr8e delivers this end to end: app audit, migration strategy, incremental modernization, testing and release.
- Phased modernization—no risky rewrite
- Objective-C to Swift & Java to Kotlin migration
- Performance, UI & OS-compatibility upgrades
- App Store & Google Play rating protected
Business outcomes
Built to fix what's broken, not rebuild what isn't.
Integr8e approaches app modernisation as a business capability—not an isolated technical task. Priorities stay connected to the users, operations and results behind the work.
An app that runs on current OS versions again
Migrate Objective-C to Swift or Java to Kotlin, update deprecated APIs and SDKs, and remove the technical debt blocking new iOS and Android releases.
Performance and ratings users notice
Fix the slow screens, crashes and outdated UI patterns that are actually driving low App Store and Google Play ratings.
A codebase your team can extend again
Leave the app on an architecture and dependency set your team—or ours—can safely add features to, instead of one more workaround away from unmaintainable.
What we deliver
Mobile app modernization services from audit to a modernised release.
One connected team covers the decisions and delivery work needed to move from uncertainty to a dependable outcome.
App audit & modernization strategy
Assess the current codebase, crash data, store ratings and technical debt to choose the right strategy—refactor, migrate, or targeted rebuild.
Objective-C to Swift & Java to Kotlin migration
Migrate legacy native code to current languages and frameworks in incremental, testable phases instead of a single risky cutover.
UI & UX modernization
Rebuild outdated screens and interaction patterns against current Apple Human Interface Guidelines or Google Material Design.
Performance & stability engineering
Diagnose and fix the crashes, memory issues and slow screens behind poor reviews and high uninstall rates.
Platform & OS compatibility upgrades
Update the app for current iOS and Android versions, deprecated APIs and new App Store or Google Play requirements.
Modernised release & growth
Manage the App Store and Google Play release, monitor crashes and ratings, and continue improving using real usage data.
Is this the right fit?
Best suited for product and engineering teams running a live mobile app on an outdated SDK, deprecated language version, or UI that's costing them ratings, performance or the ability to ship new features.
Not every challenge needs the same team or solution. We start by testing the business case, current constraints and fastest credible route to value—then recommend a scope that fits the evidence.
Delivery architecture
A controlled path from app audit to a modernised, stable release.
The plan adapts to your context, while short feedback loops and visible milestones keep the engagement controlled.
- 01
Audit
Assess the current app's codebase, crash data, store ratings and technical debt before recommending a modernization strategy.
- 02
Plan
Choose the approach—refactor, incremental migration or targeted rebuild—based on risk, cost and business priority.
- 03
Modernise
Migrate code, update dependencies and rebuild outdated screens in incremental, testable phases.
- 04
Assure
Test devices, OS versions, performance and store compliance before each phase reaches production.
- 05
Release & improve
Ship the modernised app, monitor crashes and ratings, and continue improving using real usage data.
Technology context
Tools chosen around the problem—not the trend.
We select platforms against security, scale, team fit, integration needs and the full cost of ownership.
- Swift
- Kotlin
- SwiftUI
- Jetpack
- Firebase
- REST APIs
Frequently asked questions
Answers about app modernisation.
Need an answer specific to your environment? Share the context and our team will help you identify a practical next step.
What is mobile app modernization?
Mobile app modernization updates an existing iOS or Android app's code, architecture, UI or platform compatibility so it stays fast, secure and maintainable—without necessarily rebuilding it from scratch. Integr8e delivers this end to end: app audit, migration strategy, incremental modernization, testing and release.
What's the difference between modernising an app and Integr8e's legacy system modernization service?
This service modernises the mobile app itself—its code, UI, platform compatibility and store presence. Integr8e's legacy system modernization service covers backend systems, infrastructure and architecture, such as monolith-to-microservices migration or mainframe replacement. Most clients need one or the other; some need both, and we scope that during discovery.
How do I know if my app needs modernization or a full rebuild?
Modernization usually makes sense when the core product works but specific parts—outdated language versions, deprecated APIs, poor performance, dated UI—are causing real problems. A full rebuild is worth considering when the architecture itself can't support the product's direction, or when the cost of continuing to patch it exceeds a fresh build. Integr8e audits the app first rather than defaulting to either answer.
Can you migrate Objective-C to Swift or Java to Kotlin without breaking the app?
Yes. Integr8e migrates legacy native code in incremental, testable phases, running the existing and updated code side by side where needed, so the app keeps working in production throughout the migration rather than a single high-risk cutover.
How much does mobile app modernization cost?
Cost depends on the app's size, technical debt and chosen approach—refactoring a specific module costs less than a full rearchitecture. Integr8e audits the app first and provides a phased estimate with clear assumptions rather than a generic day rate.
How long does a mobile app modernization project take?
A focused modernization addressing specific performance or compatibility issues can take a few weeks, while a full rearchitecture of a large app can take several months delivered in phases. Integr8e defines milestones after the audit instead of giving an unreliable one-size-fits-all timeline.
Will modernising the app affect its App Store or Google Play rating and existing users?
Handled correctly, no—existing users should see a faster, more stable app, not a disruption. Integr8e tests feature parity and store compliance before each phase ships, and phases releases so ratings and reviews are protected rather than put at risk by a single risky relaunch.
Who owns the modernised app and code after delivery?
Ownership and licensing are defined in the engagement agreement before delivery begins. We provide maintainable source code, App Store Connect and Google Play Console access, and practical documentation so your team can operate and evolve the app without hidden technical dependency.
Can a modernised app integrate with our existing systems and APIs?
Yes. Modernised apps can connect to CRM, ERP, payment, identity and analytics systems through REST or GraphQL APIs, webhooks, or a dedicated integration layer, alongside the existing infrastructure already in place.
What support is available after the modernised app launches?
Integr8e can provide crash monitoring, OS compatibility updates, App Store and Google Play metadata management, performance improvement and feature development after launch, matched to how actively the app is used.
Start with the outcome
Let's make your app modernisation initiative concrete.
Tell us what needs to change, who it affects and where the current approach falls short. We'll help shape a sensible next step.
hello@integr8e.com