Swift

Swift is the programming language Apple wrote for its own machines, which means the iPhone, iPad, Mac, Watch and Apple TV. So if you want an app people install from the App Store and find on their home screen, Swift is the supported way to build it.

The reason to use it is access, because Apple deliberately keeps a website in Safari at arm's length from the phone. Swift is let into the parts a web page cannot touch. It holds the camera as a live picture instead of a file chooser, and reads Face ID from the sealed chip that keeps the fingerprint. It can also follow a location while the app is closed, push a message when the app is shut, and sit on the home screen as a small panel. For a delivery driver, or a nurse scanning a wristband, that gap is the whole project.

Two costs catch owners out, and the first arrives before a single line is written. You cannot build an iPhone app on a Windows machine, because Apple's tools only run on a Mac. That puts a Mac in the budget for every developer, and another for whoever takes over later. Apple then charges around ninety-nine dollars a year for the account that keeps your app in the store. Stop paying and the app comes down, even though it still works on the phones that already have it. Every update goes through a review as well, usually a day or two, which is why a Friday fix is not live on Friday.

Swift code does not run on Android, and Android is most phones in most of our markets. So the real question is rarely Swift or not, but whether you build one app for both or two. That is why Linkysoft asks which phones your customers actually carry before anyone writes a line. Often the honest first step is a web application that behaves well in a phone browser, and the installed app follows once demand is proven.

When the app really does need Swift, the good part is what comes with it. Signing in by face or fingerprint takes very little code, and the key never leaves that sealed chip, which beats any password screen you could design. Our security reviews lean on that rather than on a login we invented ourselves. Linkysoft writes the iPhone side in Swift inside the same mobile app project as the Android side, so the two halves stay honest with each other.