Rebuild or upgrade an ageing app so it is faster, easier to maintain and accepted by the app stores.
Stack we work in
Figures as of Oct 2026
Trusted by
Many apps built five or more years ago now struggle: they crash on new phones, fail app store requirements, are slow, or are built on frameworks that are no longer supported, such as Xamarin, or are hard to hire for, such as Cordova and older Ionic.
We assess your app, then either upgrade it in place or rebuild it in Flutter or React Native, moving users and data across without losing ratings or reviews. The goal is an app your team can keep improving, not a one-off rescue.
Xamarin, PhoneGap or old Cordova versions no longer get fixes or new OS support.
Updates are blocked by target API level, SDK or privacy requirements.
Ratings drop as the app struggles on new phones and OS versions.
Old code and libraries make small features slow and risky to ship.
Separate iOS and Android codebases drift apart and cost twice as much to run.
Outcomes
Code, security and compliance findings with an upgrade versus rebuild recommendation.
An upgraded or rebuilt app released under your existing store listings.
Automated tests, CI/CD and crash monitoring.
Architecture notes and guides for your team, plus all source code in your repositories.
Know what you have before deciding.
Built with
One modern codebase for iOS and Android.
Built with
Keep the code, bring it up to date.
Built with
Make the app feel fast again.
Built with
Move everything safely.
Since 2018 we have delivered 680+ projects for 310+ clients, and 98% of clients keep working with us.
We assess your code, libraries and store warnings first, and recommend upgrading in place when a rebuild is not needed.
We move apps off Xamarin, Cordova and Ionic and upgrade old native, Flutter and React Native code.
We plan data migration and release the new version under the same store listing, so ratings and users carry over.
We keep the app current with each new iOS and Android version after modernization.
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You receive Assessment report
We compare upgrading in place with rebuilding, with costs, timelines and risks for each.
You receive Recommendation and plan
Tests, CI and monitoring are added first so we can change the app safely.
You receive Safety net in place
We upgrade or rebuild in stages, with regular test builds and demos.
You receive Test builds each iteration
User data and accounts move across, and the new version rolls out in phases.
You receive New version live in the stores
Monitoring, fixes and a roadmap for new features.
You receive Support plan
Tech stack
Databases
Mobile
Frontend
Backend and APIs
Languages
Cloud and DevOps
Other tools
Engagement
An app upgrade or rebuild built against an agreed scope, timeline and price.
Mobile developers who take over and modernize your app, full time or part time.
A short paid review or pilot that answers the key questions before you commit to a full build.
It depends on the size of the app, how much of it can be kept, the backend and the data that has to move. We start with an assessment and send a written estimate. As a guide, an app assessment usually costs $2,000 to $6,000, an upgrade in place $10,000 to $40,000, and a full rebuild in Flutter or React Native $30,000 to $120,000 or more (USD).
Upgrade when the code is in a supported language and framework and the main problems are outdated libraries or performance. Rebuild when the framework is unsupported, the code is very hard to change, or you want one codebase for iOS and Android. Our assessment compares both with costs.
Microsoft ended Xamarin support in May 2024, so apps need to move. We rebuild Xamarin apps in Flutter or React Native, keeping the same store listings so users get the new app as an update.
Yes. Cordova and older Ionic apps often feel slow and have plugin problems on new OS versions. We rebuild them in Flutter or React Native for a faster, more native experience, or upgrade Ionic with Capacitor where that is enough.
No, if done correctly. We publish the new app under the same App Store and Google Play listing, so ratings and reviews stay, and migrate accounts, local data and subscriptions so users carry on where they left off.
Often, yes. Flutter add-to-app and React Native brownfield integration let new screens live inside the existing app, so you can release improvements while the rest is migrated.
Common reasons are an outdated target API level on Google Play, an old SDK or Xcode version on the App Store, missing privacy manifests or outdated payment rules. We fix the immediate issue and set up a process so it does not happen again.
Yes, when needed. If the old API or backend is blocking the app, we update it or build a new one alongside, and migrate the data.
An assessment takes 1 to 2 weeks. Upgrades in place usually take 4 to 10 weeks. Full rebuilds usually take 3 to 6 months, depending on the size of the app.
Yes. We offer monthly maintenance covering OS and store updates, dependency upgrades, monitoring and new features.
We start with a short discovery call under NDA if you need one. Send us your idea, any designs or documents, and the systems the work must connect to. We then share a written scope, timeline and estimate before any build work starts.
Xamarin to Flutter or React Native
A full rebuild under the same store listings.
Learn moreCordova or Ionic to Flutter or React Native
A faster, more native app with modern plugins.
Learn moreObjective-C to Swift and SwiftUI
Native iOS apps upgraded screen by screen.
Learn moreOlder Android apps to Kotlin and Compose
Native Android apps upgraded in stages.
Learn moreTwo native apps to one codebase
Separate apps merged into Flutter, React Native or Kotlin Multiplatform.
Learn moreBook a call with our mobile team. We will look at your app and tell you whether to upgrade or rebuild, and what it will take.
