Swift iOS development
Swift is the answer once you know you need native iOS. That usually happens for one reason: the app has to do something the device does, and a bridge to a cross-platform framework sits between you and it.
01Capabilities
Four products where the phone is the point
Native iOS is a choice with a cost attached, so we make it deliberately. The decision before this page is native or cross-platform, and that one lives on iOS and Android. Once native iOS is settled, Swift is where the work happens, and it takes these four shapes.
- Sensors
Apps built on device capabilities
Bluetooth peripherals, camera and video pipelines, sustained background location, sensors and NFC. There is no plugin to wait for and no bridge to profile, which is the entire argument for being here rather than in a cross-platform framework.
- Security
iOS clients handling sensitive data
Keychain, the Secure Enclave, biometric unlock and on-device encryption, in products like healthcare apps and fintech apps where the answer to what leaves the phone has to be exact and defensible.
- Fleet
iPad and managed-fleet apps
Apps distributed to company-owned devices through mobile device management rather than the public store, used by people on shift in places like logistics operations. Offline behaviour and sync conflict handling are the real work, not the screens.
- Rescue
Rescuing and modernizing existing iOS apps
Apps in the store that nobody has been able to change safely for a while, including Objective-C codebases moving onto Swift. That is legacy modernization work that happens to be on a phone.
02Fit
Choosing between Swift and one shared codebase
Choosing Swift is choosing to run two codebases instead of one. So the case for it has to be about the device, not about the language. We build native iOS when the platform itself is central to the product, and one shared codebase when the app is mostly forms, lists and network calls. Each row below names the route that fits, from native Swift to React Native or Flutter, most of them on a page of their own.
| Your situation | What we recommend |
|---|---|
| Bluetooth peripherals, a camera pipeline, or location that has to keep running in the background | Use SwiftEvery cross-platform route to these ends in native code anyway, and then you maintain the bridge as well as the feature. |
| You already run a React and TypeScript team, and the app is conventional screens | Different pageOur React Native page. Sharing people and validation rules with your web product beats a slightly better platform binding. |
| Both platforms, one design language, and it has to look identical on each | Different pageOur Flutter page. It draws its own widgets, so identical is the default rather than an ongoing fight. |
| Both platforms, budget for one mobile team, and requirements that are mostly screens over an API | Decide that firstTwo native codebases means two release calendars and two versions of every bug. Start at iOS and Android. |
| The app already exists in Objective-C and you want it moved onto Swift | Migrate in stepsModule by module, with a shippable app at every step, as covered on our Objective-C page. |
| You want it in the store next month, and the design is not finished | Cut the releaseNo language fixes a scope that is still moving. A shorter first version ships on any stack, and an unfinished design ships on none. |
Scope
What we own is the recommendation and everything after it. That means the oldest iPhone the app still supports, and who that leaves out. It means which parts of the interface use which Apple toolkit, and whether your own team can keep changing the app after we stop. unicrew has been building software since 2012, with 100+ senior in-house engineers across six countries. The work runs under an ISO 27001:2022 certified information-security management system. Where one shared codebase serves the product better, that is what we recommend.
03Delivery
The four calls we make in week one
Each of these is cheap to settle now and expensive to reverse once feature work has spread across the codebase. So they are the first week, not the second month.
- Settle the oldest iPhone you still supportIt decides which Apple features are available to you, how much of the newer interface toolkit you can lean on, and which of your users get left behind. That is a product decision with data behind it, so we make it with you and write down who it excludes.
- Draw the line between the two interface toolkitsApple ships an older toolkit and a newer one, and both belong in a serious app. A codebase where nobody agreed the boundary is the most common inherited mess in iOS. We decide which screens use which, and how the two are allowed to host each other.
- Get the concurrency model right before featuresConcurrency is how the app does several things at once without corrupting its own state. Swift's approach changes how a codebase is structured, and retrofitting it across an app that grew without it is its own project rather than a cleanup.
- Ship through App Store review earlySigning, provisioning, privacy manifests and data-collection disclosures, exercised with a real submission long before there is much to submit. Review and device fragmentation are where iOS timelines actually slip, and every build meets our QA and test automation practice first.
04Stack
Everything this page hands you off to
The five neighbouring decisions the table keeps naming, each with a page of its own.
05Questions
What buyers ask before funding a second codebase
Answered the way we would answer them on a call. If yours is not here, it is a good first message.
Yes, and it is a normal way to start. Our Swift engineers take ownership of the architecture as well, because on iOS the decisions that cost you money are structural. Design review comes from an architect outside the delivery team, under the same QA practice as our own projects. Team extension is managed teams; handing over the outcome is mobile app development.
SwiftUI for new screens, where the oldest iPhone you support allows it, because it is less code and it reads better. UIKit where you need precise control: complex list layouts, custom text input, camera preview surfaces, or continuous gesture interaction. Mixing them is normal and supported in both directions, so the real question is where the boundary sits. A working UIKit app keeps its UIKit screens, because a rewrite needs a better reason than SwiftUI being newer.
If iOS is all you need and the app touches the device seriously, Swift. A cross-platform framework charges you the abstraction cost now, for a second platform you have not committed to. If Android is genuinely coming within the year and the app is mostly screens over an API, Flutter or React Native starts to make sense. That is a business answer rather than a technical one.
When change pressure justifies it: if you are already modifying a module, moving that module is close to free, because you were paying for the testing anyway. Objective-C still compiles and still ships, so migrating for its own sake is spend without a return, and a barely touched app can stay as it is. We work through this on the Objective-C page.
A scoping call with an engineer rather than an account manager. If the app exists, we ask for the repository and the crash reporting first, because crash-free rate by version and device tells us more in an hour than a week of description. If it does not, we want the hardest thing it must do on the phone. Most engagements start within two to four weeks.
Three shapes, and which one fits depends on how settled the scope is. Time and materials is billed hourly and quoted per project, which suits work still moving. Fixed price is outcome based and quoted per project, offered once the first read is done. Team extension is billed monthly per engineer. The rate depends on the seniority mix the work needs, so it is quoted rather than listed.
Building a native iOS app, or keeping one alive?
Tell us what the app has to do on the device, and who uses it. You will get a straight read on the build, native Swift or one shared codebase, decided by what the device work requires.