Tuist

Swift

swiftlang/swift

Popular

Apple's safe, fast compiled language for iOS, macOS, watchOS and visionOS apps, also used on servers.

SwiftUI

developer.apple.com

Popular

Apple's declarative UI framework for building apps across all Apple platforms in Swift.

UIKit

developer.apple.com

Apple's imperative UI framework for iOS; still powers most existing apps and interoperates with SwiftUI.

Kotlin

JetBrains/kotlin

Popular

JetBrains' concise, null-safe JVM language; Google's preferred language for Android and the base of KMP.

Jetpack Compose

developer.android.com

Popular

Android's modern declarative UI toolkit, recommended by Google for all new Android UI.

Xcode

developer.apple.com

Popular

Apple's IDE and toolchain required to build, sign, profile and ship apps for Apple platforms.

Android Studio

developer.android.com

Popular

Google's official IntelliJ-based IDE for Android development, with emulators, profilers and Gemini assistance.

Objective-C

developer.apple.com

Legacy

Apple's original app language; still found in older iOS/macOS codebases, but Swift is used for new work.

Java (Android)

developer.android.com

Legacy

Android's original app language; common in older codebases, while Kotlin is now the default for new code.