Mobile App Development
Build fast, beautiful apps for Android and iOS — natively or cross-platform.
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What is Mobile App Development?
Mobile developers build the apps people use every day on Android and iOS — banking, ride-sharing, food delivery, health, education and games. You can specialise natively (Kotlin for Android, Swift for iOS) or use cross-platform frameworks like Flutter and React Native to ship to both platforms from one codebase. Modern mobile work increasingly includes on-device AI, offline-first design, payments and accessibility.
Why it's trending now
- Smartphones are the main — often only — internet device for billions of people, including most users in Bangladesh, so businesses build 'mobile-first'.
- Cross-platform tools matured: Flutter and React Native (with its New Architecture) power major production apps, and Compose Multiplatform for iOS reached stable in 2025, letting small teams target both platforms.
- On-device AI (Apple Intelligence, Gemini Nano on Android, Core ML, LiteRT) opens a new wave of smart features that need mobile engineers who understand ML integration.
- In Bangladesh, MFS apps (bKash, Nagad), ride-sharing, e-commerce and banking apps keep mobile developers in steady demand, and Paylab lists iOS developers among the better-paid IT roles.
Job roles
Common job titles you'll see in listings, and what each one actually does.
Android Developer
Builds native Android apps with Kotlin and Jetpack Compose.
iOS Developer
Builds native iPhone/iPad apps with Swift and SwiftUI.
Flutter Developer
Builds cross-platform apps for Android, iOS and web with Dart and Flutter.
React Native Developer
Builds cross-platform apps with TypeScript and React Native, often sharing logic with a web team.
Mobile QA / Automation Engineer
Tests apps across devices with automated UI tests (Espresso, XCTest, Maestro, Appium).
Mobile Tech Lead
Owns app architecture, release process, performance and mentoring for a mobile team.
Skills from beginner to advanced
Tick skills as you learn them — your progress is saved in this browser.
1Beginner
Start here2Intermediate
Job-ready core3Advanced
Stand outMost-requested languages & tools
What employers mention most often in current job listings for this field.
Languages
Tools & platforms
Native Kotlin/Swift roles pay well at product companies; Flutter is especially popular in Bangladesh and South Asia for agency and startup work.
30/60/90-day roadmap
About 1–2 hours a day. Tick goals as you complete them.
Days 1–30
Language and first app
Milestone: A small to-do app running on your own phone.
Days 31–60
Real-world features
Milestone: A data-driven app with login, offline support and a clean architecture.
Days 61–90
Ship to a store
Milestone: A published app on Google Play or TestFlight with real users.
Free learning resources
All free to start. Some courses offer paid certificates — auditing is free.
- Android Basics with ComposeGoogle · Course · developer.android.comFree
- Develop in Swift tutorialsApple · Course · developer.apple.comFree
- SwiftUI tutorialsApple · Docs · developer.apple.com
- Flutter — Get startedFlutter · Docs · docs.flutter.dev
- React Native docsMeta · Docs · reactnative.dev
- Expo tutorialExpo · Course · docs.expo.devFree
- Kotlin KoansJetBrains · Practice · kotlinlang.orgFree
- 100 Days of SwiftUIHacking with Swift · Course · hackingwithswift.comFree
- Firebase documentationGoogle · Docs · firebase.google.com
- Android Developer roadmaproadmap.sh · Guide · roadmap.sh
Portfolio project ideas
Build these in order. Put each one on GitHub with a clear README and a short demo.
Expense tracker
easyAdd, edit and categorise expenses in BDT, with monthly totals and local storage.
News or prayer-times reader
easyFetch and display data from a public API with pull-to-refresh, caching and dark mode.
Bus route & fare finder
mediumShow city bus routes on a map, search by stop, estimate fares and work offline.
Habit tracker with notifications and sync
mediumDaily habits with reminders, streaks, charts and cloud sync via Firebase.
On-device AI receipt scanner
hardScan receipts with the camera, extract totals using on-device OCR/ML, categorise spending and export reports — all with privacy-first local processing.
10 interview questions
Try answering out loud first, then open the short model answer.
1Native vs cross-platform — how do you choose?
Native gives the best performance and earliest access to platform APIs; cross-platform (Flutter/React Native) saves time with one codebase. Choose by team skills, performance needs, budget and platform-specific features.
2Explain the Android activity lifecycle (or iOS app lifecycle).
Android activities move through onCreate, onStart, onResume, onPause, onStop and onDestroy; you save state and release resources at the right points. iOS has similar scene states: active, inactive, background, suspended.
3What is MVVM?
Model–View–ViewModel separates UI (View) from presentation logic (ViewModel) and data (Model). The View observes ViewModel state, making code testable and lifecycle-safe.
4How do you make an app work offline?
Store data locally (Room/SQLite/SwiftData), show cached data first, queue user actions, and sync with the server when connectivity returns, resolving conflicts.
5How do you avoid a frozen UI?
Never do heavy work on the main thread — use coroutines, async/await, isolates or background threads for network, disk and computation.
6What is state management in Flutter/React Native?
How app data that affects the UI is stored and updated. Small apps can use local state; larger apps use Riverpod/Bloc (Flutter) or Redux/Zustand/React Query (RN) for predictable updates.
7How do push notifications work?
The app registers with FCM (Android) or APNs (iOS) to get a device token, your server sends messages to that service, and it delivers them to the device.
8How do you store sensitive data securely?
Use Android Keystore / EncryptedSharedPreferences or iOS Keychain, never hard-code secrets, and use HTTPS with proper certificate validation.
9How would you reduce app startup time?
Profile it, defer non-essential initialisation, lazy-load modules, reduce work in the first screen, and use baseline profiles (Android) or optimise launch tasks (iOS).
10How do you test mobile apps?
Unit tests for logic, UI tests (Espresso/Compose tests, XCTest, Flutter integration tests or Maestro), and testing on a range of real devices and OS versions.
Resume bullet templates
Replace the [brackets] with your real numbers. Quantified results stand out to recruiters.
Built and published [app] on Google Play/App Store with [N]+ downloads and a [X]-star rating.
Reduced app crash rate from [X]% to [Y]% by adding Crashlytics monitoring and fixing top [N] issues.
Cut cold-start time by [X]% through lazy initialisation and baseline profiles.
Implemented offline-first sync for [feature], enabling use in low-connectivity areas and increasing daily active users by [X]%.
Migrated [N] screens from [XML/UIKit] to [Jetpack Compose/SwiftUI], reducing UI code by [X]%.
Formula: action verb + what you built + tools + measurable result. Only claim numbers you can explain in an interview.
Salary & demand
Ranges vary by company, city, experience and negotiation. Always check the linked sources for the latest figures.
Bangladesh
Tk 16,942 – Tk 79,837
gross per month
Combined Paylab ranges for Android Developer (BDT 16,942–73,707) and iOS Developer (BDT 18,958–79,837), 10th–90th percentile, gross monthly.
Demand
High. Fintech/MFS, e-commerce, ride-sharing and agencies hire mobile developers; Flutter roles are especially common in local postings.
Remote (from Bangladesh)
$25,000 – $70,000
per year
Arc reports Bangladesh-based remote app developers average $38,685 per year and senior developers $69,548.
Demand
Good demand, especially for Flutter and React Native freelancers who can deliver both platforms; native iOS/Android specialists earn more.
Global benchmark
$134,040
US median, Software Developers, QA Analysts & Testers (BLS, 2025)
Mobile engineers are counted within software developers by BLS. Projected growth: +10% (2025–35, much faster than average).
Demand
High and stable. Mobile remains the primary channel for consumer products worldwide.
How to read these numbers: Bangladesh ranges are Paylab's 10th–90th percentile gross monthly salaries (top product companies often pay more). Remote ranges are CareerPulse estimates informed by Arc's Bangladesh remote-developer data. Global figures are US medians from the Bureau of Labor Statistics (May 2025 data, 2025–35 projections) unless stated otherwise.
Start today checklist
Small, concrete actions you can finish today. Momentum beats perfect plans.