How to build · 05

Mobile Development

React Native and Expo, Flutter and Dart, Kotlin and SwiftUI, navigation, device APIs, push and publishing.

Read: 0 / 12Mobile Fundamentals React Native & Expo Mobile Navigation State Management Flutter & Dart Flutter Kotlin & Android Swift & SwiftUI Device APIs Push Notifications Mobile Testing App Publishing

Mobile Fundamentals

Comparison✓
Mobile development: native, React Native or Flutter
Native development means two separate apps: Kotlin with Jetpack Compose for Android and Swift with SwiftUI for iOS, with full access to every platform API. React Native (usually together with Expo) lets you write one app in TypeScript using the React model, while the screen shows real native components. Flutter also gives you one codebase, but in Dart, and draws the UI with its own engine; the choice between them depends on the device APIs you need, your team and how much platform code you are willing to maintain.
Beginner · 9 min read

React Native & Expo

Tutorial✓
React Native and Expo: your first app
The easiest way to start a React Native project is npx create-expo-app@latest: it creates an Expo app with TypeScript and file-based navigation, and npx expo start opens it in Expo Go on your phone, in an emulator or in the browser. A screen is built from the View, Text, Image, Pressable and ScrollView components, and styles are objects passed through StyleSheet — no CSS files, with Flexbox that lays elements out in a column by default.
Beginner · 9 min read · practice ~1.5–3 h

State Management

Tutorial✓
React Native: API requests and local storage
React Native loads server data with the same fetch as the browser, but a screen has to survive a bad network: it needs loading, error, empty and “cached data” states. Settings and cache go into AsyncStorage — an unencrypted string store — while tokens and other secrets belong in expo-secure-store, which encrypts values with the iOS Keychain and the Android Keystore. Once you have many requests, TanStack Query replaces the hand-written code, and large relational data goes into SQLite.
Intermediate · 8 min read · practice ~1.5–3 h

Flutter & Dart

Tutorial✓
Flutter and Dart: your first app
A Flutter app is a tree of Dart widgets: runApp receives the root widget, MaterialApp provides theming and navigation, and a screen is composed from Scaffold, Column, Row, Expanded and other layout widgets. Widgets without mutable data extend StatelessWidget, while data that changes with user actions lives in the State of a StatefulWidget and is updated with setState. The Dart you need to start is null safety (String?), classes with named parameters and async/await.
Beginner · 9 min read · practice ~1.5–3 h

Flutter

Tutorial✓
Flutter: state and navigation
In Flutter, a single widget’s local state lives in State and changes through setState, while data needed by several screens moves into a ChangeNotifier model shared with the provider package: context.watch in build, context.read in handlers. For navigation there is Navigator (push/pop, data through the constructor, a result through pop), and for addresses and deep links the docs recommend go_router: a /notes/:id route, context.go and context.push.
Intermediate · 8 min read · practice ~1.5–3 h

Kotlin & Android

Tutorial✓
Android with Kotlin and Jetpack Compose: your first screen
A Jetpack Compose screen is a set of Kotlin functions annotated with @Composable that describe the UI for the current state: change a value in mutableStateOf and Compose redraws the affected parts. In this lesson we build a services list screen: a Kotlin model, a card made of Row, Column and Box, selection with remember, a LazyColumn list, Material 3 styling and a ViewModel so the selection survives screen rotation.
Beginner · 11 min read · practice ~1.5–3 h

Swift & SwiftUI

Tutorial✓
iOS with SwiftUI: your first screen
A SwiftUI screen is made of structs that conform to the View protocol: the body property describes the UI, and SwiftUI updates it when data in @State or in an @Observable model changes. You need a Mac and Xcode (currently Xcode 27 with the iOS 27 SDK and Swift 6.4); Swift models and logic can be tested off the Mac, but SwiftUI itself builds only in Xcode.
Beginner · 10 min read · practice ~1.5–3 h

Device APIs

How-to✓
Camera, location and permissions: device APIs
An app gets camera, location and photo access in two steps: at build time it declares the permissions (the Android manifest and iOS Info.plist purpose strings — in Expo via app.json and config plugins), and at runtime it asks the user. Ask at the moment the person starts the feature, and only for what that feature needs. After a denial the system dialog may never appear again — then the screen explains what's unavailable, offers a workaround and a button that opens Settings.
Intermediate · 7 min read · practice ~1–2 h

Push Notifications

How-to✓
Push notifications: how they work and how to connect them
Your server sends a push notification, and a platform service delivers it to the phone: Firebase Cloud Messaging on Android and Apple Push Notification service on iOS. The app obtains a token — the device's address for that service — and passes it to your server; in Expo this is the ExpoPushToken, and the server sends messages through Expo Push Service, which talks to FCM and APNs for you. On SDK 57 push doesn't work in Expo Go: you need a development build, FCM credentials and a paid Apple Developer account for iOS.
Intermediate · 7 min read · practice ~2–4 h

Mobile Testing

Fundamentals✓
Testing mobile apps
A mobile app is tested at three levels: unit tests for logic, component tests (widget tests in Flutter) for screens, and E2E tests on an emulator or a device for key flows. In React Native and Expo the first two levels are covered by Jest and React Native Testing Library, in Flutter by the flutter_test package; for E2E teams use Maestro, Detox or integration_test. Automated tests don't replace manual checks on real devices and test builds distributed through TestFlight and Google Play internal testing.
Intermediate · 9 min read

App Publishing

How-to✓
Publishing to the App Store and Google Play
To release an app you need Apple Developer Program and Google Play Console accounts, unique app identifiers, signed release builds (.ipa and .aab) and complete store listings with a privacy policy and data disclosures. In Expo, EAS Build and EAS Submit automate building and uploading; in Flutter you use flutter build appbundle and flutter build ipa. Most rejections come from unfinished apps: crashes, placeholder content, broken links and no demo account for the reviewer.
Intermediate · 11 min read · practice ~1–2 h

Learning paths with this direction

React Native + Expo · 9 →Flutter + Dart · 6 →← All directions

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