Legacy iOS app modernization brings an aging iPhone or iPad app back to a stable, supportable state without throwing away the business logic it took years to build. We migrate Objective-C to Swift, refactor UIKit screens toward SwiftUI, recover abandoned codebases and fix the compliance gaps that put App Store listings at risk. Most clients come to us after the original developer has disappeared. The first step is a fixed-scope iOS modernization audit, so you get a clear diagnosis before committing to any rebuild.
Book a Modernization Audit →Legacy apps rarely fail in one dramatic moment. They decay: each iOS release brings new warnings, builds take longer, and simple changes start costing weeks. Many owners only act when Apple rejects an update or a key customer reports a crash on a new iPhone. Spotting the warning signs early keeps your options open, because a planned modernization costs far less than an emergency rescue under deadline pressure. If several of these signs sound familiar, it is time for an assessment.
If each Xcode update brings a day of fixing build errors, or your team keeps an old Mac running just to compile, the codebase has fallen dangerously behind Apple's toolchain.
Libraries that stopped receiving updates years ago, CocoaPods specs that no longer resolve, or SDKs your vendor deprecated all create security exposure and block the platform upgrades you need next.
When adding a field or a button touches dozens of files, the architecture is working against you. Lost velocity is often the most expensive symptom, even when nothing visibly breaks for users.
Layout glitches on new screen sizes, deprecated API warnings and rising crash rates after each September release signal an app that was never updated to match Apple's ongoing platform changes.
Objective-C is still supported, but the talent pool, tooling and new Apple frameworks have moved firmly to Swift. Migrating does not have to mean a risky big-bang rewrite. Swift and Objective-C interoperate inside the same project, which allows a phased migration that keeps your app shippable throughout. Our approach converts the code that changes most often first, protects it with tests, and leaves stable, rarely touched Objective-C until last, or permanently when that is the cheaper option.
Bridging headers and careful nullability annotations let Swift and Objective-C call each other safely. Clean bridging is what makes incremental migration practical for product teams, rather than a long and costly feature freeze.
We analyze version control history to find the files that change most and break most often. Migrating those first delivers the biggest productivity gains with the lowest overall risk to the product.
Untested legacy code is converted only after characterization tests capture its current behavior. Those tests confirm that the Swift version does exactly what the Objective-C version did, edge cases included.
Converted code adopts Swift concurrency, value types and current architecture patterns rather than line-by-line translation. Our Swift and SwiftUI development team applies the same standards it uses on brand-new builds.
SwiftUI has matured into Apple's preferred UI framework, and new platform features increasingly arrive there first. Still, rewriting every UIKit screen at once is rarely sensible. The two frameworks interoperate well, so we introduce SwiftUI where it adds the most value, such as new features, settings screens and widgets, while complex, stable UIKit screens stay in place until there is a reason to touch them. This keeps legacy iOS redesign development services focused on user impact rather than technical fashion.
UIHostingController lets new SwiftUI screens live inside an existing UIKit navigation structure. Teams can ship SwiftUI features immediately without first restructuring the whole app or pausing the current release schedule.
We build a reusable SwiftUI component library that matches your current branding and visual design, so users see one consistent interface while the underlying framework changes quietly, screen by screen.
Many legacy apps hide business logic inside massive view controllers. Refactoring moves that logic into testable models and view models, which simplifies SwiftUI adoption and makes future maintenance far cheaper.
Refactored screens gain Dynamic Type, Dark Mode, better VoiceOver support and correct layouts for current devices, closing usability gaps that older, hand-coded UIKit layouts have often ignored for many years.
A large share of modernization work starts with an app nobody fully understands. The original agency closed, the freelancer stopped answering, or the internal developer left without documentation. We treat these situations methodically: recover access, establish a reproducible build, map how the system works and identify the highest risks before writing any new code. You get a clear picture of what you own, what it depends on and what it will realistically take to keep it running.
We help you regain control of source repositories, Apple Developer accounts, signing certificates, push notification keys and backend credentials, often the most urgent and most overlooked part of an inherited app.
Before any change, we get the app compiling on the current Xcode from a clean machine and document every step, so builds never again depend on one person's laptop or memory.
We produce architecture diagrams, dependency inventories and data flow notes that explain how the app actually works, giving your team and any future developers a reliable reference point for decisions.
Security holes, deprecated APIs and fragile integrations are ranked by business impact and urgency, so the first fixes protect revenue and users rather than polishing low-risk code nobody will notice.
Apple raises minimum SDK requirements, introduces new privacy rules and tightens review guidelines every year. Apps that have not been updated in a while can be removed from sale or blocked from shipping updates, often surprising owners who are not watching closely. Modernization brings the app back in line: current SDK builds, accurate privacy disclosures, required account deletion and up-to-date third-party SDKs. This protects your listing, your ratings and the existing user base you have spent years building.
Apple periodically requires App Store submissions to be built with recent Xcode and iOS SDK versions. We update the build toolchain so your next submission is accepted rather than rejected on technical grounds.
We audit data collection, update privacy nutrition labels and add privacy manifests for your app and its third-party SDKs, closing one of the most frequent sources of review rejections for older apps.
Apps that allow account creation must offer in-app account deletion, and some sign-in setups trigger additional review requirements. We implement these properly rather than with a hurried workaround that fails review.
Modernized apps deserve updated screenshots, descriptions and keywords. Our App Store optimization service helps a refreshed app steadily regain the search visibility and ratings it lost during its neglected years.
The modernization audit is a fixed-fee, fixed-timeline review that answers one question: what is the smartest way forward for this app? It is designed for owners who need facts before committing budget, especially after a bad experience with a previous vendor. You receive a written report and a walkthrough session, and the findings are yours to use with us, your internal team or another developer. There is no obligation to continue working with us afterward, and no sales pressure.
Senior iOS engineers review structure, code quality, test coverage and the Objective-C to Swift ratio, highlighting what is sound, what is fragile and what is actively slowing down your development team.
Every third-party library and SDK is inventoried with its version, maintenance status and known vulnerabilities, alongside a practical review of how the app currently handles data storage, networking and authentication.
We give an honest recommendation on modernizing, partially rewriting or rebuilding, with clear reasoning and estimates for each option. Sometimes a rebuild genuinely is cheaper, and when it is, we say so plainly.
Findings become a phased roadmap with effort estimates, risks and quick wins. Our iOS delivery process shows how each phase moves from planning through development to a tested, released update.
Legacy iOS app modernization is the process of updating an older iPhone or iPad app so it builds on current tools, meets App Store requirements and becomes maintainable again. It typically includes Objective-C to Swift migration, dependency updates, UI refactoring, security fixes and documentation, while preserving the business logic users rely on.
Modernize when the core logic is sound and the main problems are outdated code, dependencies or UI. Rebuild when the architecture blocks key features, quality is poor throughout, or requirements have changed completely. If a full rebuild wins, our custom iOS app development team can scope it properly.
It depends on codebase size, test coverage and how active development is. A small app may take a few weeks, while large apps are usually migrated in phases over several months. Phased migration lets you keep shipping features throughout, so the timeline rarely means a long freeze for your product.
Yes, and most of our modernization clients arrive in exactly that situation. We help recover source code, Apple Developer account access, certificates and backend credentials, then establish a reproducible build and document the system before making changes. Fixing access and builds first prevents costly surprises later in the project.
Apple can remove apps that no longer function as expected or that have not been updated for a long time, usually after notifying the developer first. Apps built with outdated SDKs can also be blocked from shipping updates, so regular maintenance is the simplest way to protect your listing.