Programming languages in mobile development: what they are, what types exist, and how to choose

What languages are used in mobile development?

Modern mobile development uses more than a dozen programming languages, each occupying its own niche. Some languages are designed for native development on a specific platform, others for cross-platform solutions, and others for supporting tasks.

For iOS, the main languages are Swift (modern) and Objective-C (legacy). For Android — Kotlin (modern) and Java (legacy). Cross-platform frameworks such as Flutter and React Native use Dart and JavaScript/TypeScript respectively. C++, Rust, and Python are used for specific tasks: game engines, high-performance modules, build automation.

According to the Stack Overflow Developer Survey (2025), JavaScript remains the most popular language in the world (used by 62% of developers), Kotlin is in the top 20, and Swift is in the top 30. At IT Sectr, we have been using Kotlin for Android, Swift for iOS, and Dart for Flutter projects since 2017 — this set covers 95% of commercial development tasks.

Languages for iOS: Swift and Objective-C

Swift is the primary language for developing iOS, iPadOS, macOS, watchOS, and tvOS apps, introduced by Apple in 2014. Swift combines high performance (comparable to C++) with a clean and expressive syntax, type safety, and automatic memory management through ARC.

Objective-C is the legacy language used to write iOS apps before Swift arrived. Objective-C is used in older projects and some enterprise systems, but new apps are no longer written in it. According to Apple (WWDC 2025), more than 85% of new apps in the App Store are written in Swift.

Swift is actively evolving: version 6.0 (2025) brought full actor support, a strict concurrency model, and Sendable. For iOS development, knowing Swift and the SwiftUI framework (UIKit for legacy support) is sufficient.

// Swift: простое приложение
import SwiftUI

struct GreetingView: View {
    @State private var name = "мир"

    var body: some View {
        VStack {
            Text("Привет, \(name)!")
            TextField("Введите имя", text: $name)
        }
        .padding()
    }
}

The Swift code above creates a screen with text and an input field — a minimal SwiftUI application that reacts to data changes. To start learning iOS, simply install Xcode on a Mac and take the free Swiftful Thinking course.

Languages for Android: Kotlin and Java

Kotlin is the main language for Android development, introduced by JetBrains in 2011 and officially supported by Google in 2017. Kotlin is fully compatible with Java but offers a more concise and safe syntax: null safety at the type level, coroutines for asynchrony, data classes, and extension functions.

Java is the original Android language, used since the platform's launch in 2008. According to Google (Android Studio, 2025), about 30% of new projects in Android Studio still use Java, but Kotlin's share is steadily growing. Java remains relevant for maintaining enterprise projects and tasks where backward compatibility is critical.

Kotlin is a modern, safe, and enjoyable language. If you are starting with Android — choose Kotlin. Learn Java only if you need to maintain an existing project.

// Kotlin: простое приложение
class MainActivity : AppCompatActivity() {
    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)

        val greeting = "Привет, Android!"
        TextView(this).apply {
            text = greeting
            setTextSize(COMPLEX_UNIT_SP, 24f)
            setContentView(this)
        }
    }
}

The Kotlin code uses an apply block to configure a TextView — a concise approach characteristic of the language. The equivalent Java code would take 1.5–2 times more lines. Install Android Studio and create a project with the Empty Activity template — your first screen is ready in 5 minutes.

Cross-platform languages: Dart, JavaScript, C#

Dart is a programming language from Google, created for the Flutter framework. In the same category — JavaScript/TypeScript for React Native, Ionic, Cordova, and C# for Xamarin, .NET MAUI. Cross-platform languages allow you to write one codebase for Android and iOS simultaneously.

Dart is a language from Google, created specifically for Flutter. It compiles to native code (AOT) for performance and supports hot reload for rapid development. According to Statista (2026), Flutter is used in 16% of all mobile applications, making it the most popular cross-platform framework. JavaScript and its typed superset TypeScript are the foundation of React Native, the most popular cross-platform framework until 2023. C# is Microsoft's language for Xamarin and .NET MAUI, used primarily in enterprise environments.

For beginners, we recommend first mastering one native platform, then learning cross-platform development to expand your capabilities. At IT Sectr, we use Flutter for projects where speed to market on both platforms is important, and Kotlin/Swift for projects with high performance requirements.

Supporting programming languages: Python, C++, Rust

Python, C++, and Rust are supporting programming languages used in mobile development for specific tasks: build automation, high-performance modules, game engines.

Python is used for automation scripts (build, deploy, testing), on-device machine learning (via Core ML and TensorFlow Lite), and backend. C++ is the main language for Unity and Unreal Engine game engines, as well as for NDK development on Android. Rust is a modern systems language for writing safe-native modules in cross-platform SDKs. Ruby is used in the Fastlane automation tool. Go is used for backend and CLI utilities.

Knowing C++ or Rust opens the door to high-load mobile development: games, video editors, AR/VR. However, for your first app, these languages are not required — start with Kotlin or Swift, and learn advanced languages as needed. According to IT Sectr's experience, Python is the best supporting language for automating routine tasks: writing a Python script takes 3–5 times less time than Bash.

Programming languages: Kotlin Multiplatform — one code for both platforms

Kotlin is a programming language that, with the Multiplatform technology (KMP), allows you to write shared business logic for Android and iOS. Kotlin compiles to both Android bytecode (JVM) and native iOS code (via Kotlin/Native). The UI remains native: Jetpack Compose for Android and SwiftUI for iOS.

According to JetBrains (KotlinConf 2025), KMP is already used by companies such as Netflix, Philips, and VMware for sharing logic between platforms. KMP does not replace Flutter or React Native — it is a different approach: you share only business logic (networking, database, validation), while the interface remains native. This provides better UI performance and access to all platform APIs.

KMP is a promising technology for teams that want to reduce code duplication without sacrificing native quality. Learning it requires knowledge of Kotlin and at least one platform (Android or iOS).