iOS (Swift/SwiftUI), Android (Kotlin/Jetpack Compose), React Native, and Flutter developers -- screened live on your platform, architecture patterns, and App Store/Play Store delivery. Shortlisted in 72 hours. Flat 15% fee.
Trusted by 120+ mobile product teams globally
200+
Vetted Mobile Devs
72h
To Shortlist
15%
Flat Fee
Top 5%
Acceptance Rate
200+
Vetted Mobile Devs
98%
App Store Approval Rate
$0
Matching Fee
72h
To Shortlist
15%
Flat Management Fee
14-day
Free Replacement
Mobile developers matched on your platform (iOS/Android/cross-platform), framework, and release pipeline
A bad mobile engineer does not just write slow features. They ship apps that crash in production, fail App Review, and accumulate technical debt that rewrites cannot fix cheaply. Here is how we prevent that.
Every engineer passes a live technical screen on your platform: iOS engineers are assessed on Swift concurrency (async/await, actors), SwiftUI state management (ObservableObject, @StateObject, TCA), and Core Data or SwiftData. Android engineers on Kotlin coroutines, Jetpack Compose state hoisting, and MVVM/MVI architecture. React Native and Flutter engineers on their respective state management patterns and native module bridging. No self-reported claims.
An iOS SwiftUI engineer is not interchangeable with an Android Jetpack Compose engineer, which is not the same as a React Native cross-platform developer, which is not the same as a Flutter engineer. Each platform has distinct architecture patterns, performance constraints, and App Store/Play Store submission requirements. We maintain separate vetted pools and screening tracks for each.
We verify App Store and Play Store submission history -- not just code quality. This includes: App Store Connect management, TestFlight distribution, provisioning profile and certificate lifecycle, Play Store release tracks (internal/alpha/beta/production), and compliance with Apple App Review guidelines and Google Play policy. Engineers without live app delivery experience are not in our pool.
Shallow mobile engineers can add features to existing codebases. We screen for architecture depth: Clean Architecture and MVVM/MVI for Android, The Composable Architecture (TCA) and VIPER for iOS, scalable navigation patterns for React Native and Flutter, and offline-first data sync strategies. Engineers who understand dependency injection, testability, and modularisation produce apps that scale.
Mobile app agencies frequently charge $150-300/hr for engineers who cost $60-100/hr on the open market. Our fee is a flat 15% on the engineer rate, published in every contract before you sign. You see exactly what the engineer earns, and there is no fee to receive your shortlist.
Mobile apps that are not tested on real devices, shipped with memory leaks, or launched without crash monitoring are a product risk. Every engagement includes weekly delivery reports, crash monitoring setup (Firebase Crashlytics, Sentry), UI test coverage requirements, and a dedicated account manager. You get a managed mobile team, not an unaccountable contractor.
Anonymised profiles from our active pool. Every developer below has passed a live technical screen on their platform, architecture patterns, and App Store or Play Store delivery track record.
Senior iOS Engineer -- SwiftUI & TCA
Western Europe · 8 years
Rebuilt a fintech iOS app from UIKit to SwiftUI with The Composable Architecture. App Store rating improved from 3.2 to 4.7 stars. Implemented offline-first sync with Core Data + CloudKit. Reduced app crash rate from 2.3% to 0.08% via systematic crash monitoring triage.
Android Engineer -- Kotlin & Jetpack Compose
Eastern Europe · 7 years
Built Jetpack Compose UI from scratch for a 2M-user e-commerce Android app. Implemented MVI architecture with Kotlin coroutines and Flow. Reduced cold start time from 4.2s to 1.1s via baseline profiles. Full Play Store release track management including staged rollouts.
React Native Cross-Platform Engineer
Latin America · 6 years
Led React Native development for a health-tech app shipping to 500K users on iOS and Android simultaneously. Implemented React Native Reanimated 3 gesture-driven UI achieving 60fps on mid-range Android. Managed Expo EAS build and submit pipeline reducing release cycle from 2 weeks to 3 days.
Flutter Engineer -- Dart & Firebase
South-East Asia · 5 years
Built Flutter app for logistics company with offline-first architecture and background sync. Shipped to iOS, Android, and web from single codebase. Implemented Bloc state management with 95% unit test coverage. Integrated Firebase Auth, Firestore, and Crashlytics.
iOS & Android Native Specialist -- UIKit & XML
South Asia · 9 years
9 years shipping native iOS and Android apps across banking, retail, and healthcare. Deep UIKit expertise for brownfield app modernisation. Specialist in accessibility compliance (WCAG 2.1 AA), biometric authentication, and enterprise MDM integration. 40+ apps shipped to production.
Mobile Platform & DevOps Engineer
Eastern Europe · 7 years
Specialises in mobile CI/CD infrastructure: Fastlane lane design, Bitrise and Xcode Cloud pipeline setup, automated App Store and Play Store submission, crash monitoring with Firebase Crashlytics and Sentry, and code signing automation. Reduced manual release effort by 85% for a team of 8 mobile engineers.
All profiles are anonymised. Full profiles including App Store/Play Store links and references are shared after brief submission. Rates shown are engineer rates before the 15% management fee.
Platform-matched shortlisting in 72 hours. Every developer pre-screened on architecture, UI performance, and live app delivery history.
Tell us your target platform (iOS, Android, or cross-platform), your framework preference (SwiftUI, Jetpack Compose, React Native, or Flutter), the nature of the work (greenfield app, modernisation, feature addition), and any special requirements (offline sync, biometric auth, payment integration, accessibility). The more specific, the faster we shortlist.
iOS SwiftUI, Android Jetpack Compose, React Native, and Flutter are fundamentally different engineering disciplines. Our team reviews your brief and matches from a pool of engineers with verified App Store or Play Store delivery history on your specific platform and framework. Generalist mobile CVs are not shortlisted.
Every engineer on your shortlist has passed a live screen: platform-specific architecture assessment (SwiftUI/TCA, MVVM/MVI, Bloc pattern), Swift or Kotlin or Dart language depth, state management and concurrency model, UI performance and memory management, and App Store/Play Store submission experience. We also verify live app links where possible.
Once you select a developer, we manage the engagement: weekly delivery reports, crash monitoring setup requirements (Firebase Crashlytics or Sentry), UI test coverage, App Store and Play Store submission support, and a dedicated account manager. You get a managed mobile team with quality accountability -- not a contractor who disappears after launch. Delivery also includes App Store and Play Store signing certificate transfer -- all distribution certificates, provisioning profiles (iOS), and keystore files (Android) are documented and transferred to the client's developer account before the engagement closes.
From native iOS SwiftUI to Android Jetpack Compose, React Native, Flutter, and mobile CI/CD. Tell us your platform and stack in the brief.
SwiftUI and UIKit development for iPhone and iPad. The Composable Architecture (TCA), VIPER, and MVVM patterns. Swift concurrency (async/await, actors, structured concurrency), Combine reactive pipelines, Core Data and SwiftData persistence, and HealthKit, ARKit, and StoreKit integrations.
Jetpack Compose UI and Kotlin-first Android development. MVI and MVVM architecture with Hilt dependency injection, Kotlin coroutines and Flow for async operations, Room database with SQLite, WorkManager for background jobs, and Google Play Billing for subscriptions.
React Native development with Expo and bare workflow. TypeScript-first codebases, Redux Toolkit or Zustand state management, React Navigation, React Native Reanimated 3 for 60fps animations, native module bridging, and Expo EAS Build and Submit for automated App Store and Play Store releases.
Flutter and Dart development targeting iOS, Android, web, and desktop from a single codebase. Bloc and Riverpod state management, Firebase integration (Auth, Firestore, Crashlytics), platform channel implementation for native features, and Dart isolates for background processing.
Biometric authentication (Face ID, Touch ID, Android Biometric API), certificate pinning, keychain and keystore secure storage, jailbreak and root detection, OWASP Mobile Top 10 remediation, and PCI-DSS/HIPAA compliance for healthcare and fintech mobile apps.
App performance engineering: cold start optimisation, memory leak detection (Instruments, LeakCanary), UI rendering jank elimination, Fastlane CI/CD pipeline design, Bitrise and GitHub Actions for mobile, crash monitoring with Firebase Crashlytics and Sentry, and automated App Store/Play Store submission.
Platform choice determines the engineering hire. Here is the decision framework and the exact engineering differences between each approach.
Language: Swift (primary) / Objective-C (legacy)
UI: SwiftUI / UIKit
Architecture Patterns
Best For
Best-in-class UX, Apple ecosystem integration (HealthKit, ARKit, SiriKit, Widgets), and highest ARPU user base.
Watch Out For
Larger talent pool claims iOS experience but few understand TCA, Swift concurrency, or App Store review compliance deeply.
Deployment
App Store Connect + TestFlight
Hiring trigger
You need deep Apple platform integration or a premium UX that Android cannot replicate.
Language: Kotlin (primary) / Java (legacy)
UI: Jetpack Compose / XML View system
Architecture Patterns
Best For
Largest global user base (72% market share), Google ecosystem (Maps, Pay, Assistant), and broad device range from budget to flagship.
Watch Out For
Android fragmentation (OS versions, screen sizes, manufacturer overlays) requires broad device testing discipline -- not just emulator testing.
Deployment
Google Play Console (internal/alpha/beta/production tracks)
Hiring trigger
Your primary users are on Android, in emerging markets, or you need Google ecosystem integrations.
Language: TypeScript / JavaScript
UI: React Native components (compiled to native views)
Architecture Patterns
Best For
Single codebase for iOS + Android, faster iteration, JavaScript/TypeScript team can contribute, Expo managed workflow for rapid prototyping.
Watch Out For
New Architecture (JSI/Fabric) migration is complex. Native modules still require platform-specific code. Performance ceiling below fully native for animation-heavy apps.
Deployment
Expo EAS Build + Submit (or Fastlane for bare workflow)
Hiring trigger
You want iOS + Android from one codebase and your team has a JavaScript/TypeScript background.
Language: Dart
UI: Flutter widgets (own rendering engine -- Skia/Impeller)
Architecture Patterns
Best For
Pixel-perfect custom UI across iOS, Android, web, and desktop from one codebase. Flutter's own renderer avoids platform UI inconsistencies. Growing enterprise adoption.
Watch Out For
Dart is a smaller talent pool than JavaScript. Flutter web is production-viable but less mature than dedicated web frameworks. Some native integrations require platform channels.
Deployment
Fastlane or Flutter build commands + codemagic.io
Hiring trigger
You need iOS + Android + web/desktop from one codebase with highly custom UI, or your team is open to adopting Dart.
A quick-reference comparison across the factors that matter most when choosing your mobile platform.
| Factor | iOS Native | Android Native | React Native | Flutter |
|---|---|---|---|---|
| Performance ceiling | Highest | Highest | High | High |
| Talent pool size | Large | Largest | Large | Medium |
| Time to market | Medium | Medium | Fast | Fast |
| Codebase sharing | iOS only | Android only | iOS + Android | iOS + Android + Web |
| Apple ecosystem access | Full | None | Partial | Partial |
| Google ecosystem access | None | Full | Partial | Partial |
| Custom UI flexibility | High | High | Medium | Highest |
| Offline-first apps | Excellent | Excellent | Good | Good |
8 competency domains across iOS, Android, React Native, Flutter, architecture, performance, App Store delivery, and CI/CD. Every developer assessed live.
Skill levels reflect our minimum pool inclusion threshold. Developers specialise in one or two platform tracks -- not all eight. Platform-specific depth is prioritised over breadth.
Questions that reveal real platform depth. Generic algorithm problems tell you nothing about App Store submission experience or SwiftUI state management skill.
Walk me through how you manage state in a SwiftUI app with multiple interconnected views that need to react to async network calls and local persistence changes.
Why this question
Tests iOS state management depth: understanding of @StateObject vs @ObservedObject vs @EnvironmentObject, Swift concurrency with MainActor for UI updates, Combine publishers vs async/await, and how Core Data or SwiftData changes propagate to SwiftUI views. Strong candidates discuss TCA or clean architecture boundaries.
Red flag answer
I use @State for most things and pass data around with bindings. No understanding of the observed object graph.
Your Android app has a 3.8-second cold start time and the product team wants it under 1.5 seconds. Walk me through your diagnostic and optimisation approach.
Why this question
Tests Android performance depth: Application class initialisation profiling, lazy initialisation of SDK dependencies, App Startup library, baseline profiles for AOT compilation, and SplashScreen API. Strong candidates use Android Studio profiler and discuss specific cold vs warm vs hot start distinctions.
Red flag answer
I would reduce the number of dependencies in the app. No systematic profiling approach.
You are building a React Native app that needs to access Bluetooth LE devices for a health-tracking feature. The feature needs to work on iOS 16+ and Android 12+. What is your approach?
Why this question
Tests React Native native module depth: evaluating available libraries (react-native-ble-plx) vs building a custom native module, understanding iOS Info.plist permission strings and Android manifest permissions plus runtime permission handling differences between platforms, and Background Mode requirements on iOS.
Red flag answer
I would find a library on npm. No awareness of platform-specific permission flows or background limitations.
Describe the architecture of a Flutter app you built that needed offline-first functionality with background sync when connectivity returned.
Why this question
Tests Flutter architecture depth: local storage strategy (Hive, sqflite, or Drift), Bloc/Cubit for connectivity state, Dart isolates or Flutter background service for sync, conflict resolution strategy for optimistic updates, and connectivity_plus for network state monitoring.
Red flag answer
I cached API responses in shared preferences. No understanding of conflict resolution or background sync architecture.
An iOS app you released is getting 1-star reviews citing crashes on iPhone 12 running iOS 16.2 specifically. Describe your complete crash investigation and hotfix process.
Why this question
Tests production incident response: Firebase Crashlytics crash grouping and symbolication, Xcode Organizer for crash logs, reproducing on specific OS versions using simulators and Appetize, expedited App Store review request process, and whether the developer uses feature flags/remote config to disable features without a full release.
Red flag answer
I would look at the crash logs and fix the bug. No mention of symbolication, targeted device testing, or expedited review.
Design a mobile CI/CD pipeline for a team of 5 iOS developers shipping to TestFlight on every merged PR, with weekly production releases to the App Store.
Why this question
Tests mobile DevOps maturity: Fastlane match for code signing, Xcode Cloud or Bitrise for build infrastructure, automated version bump with agvtool or fastlane increment_build_number, TestFlight group targeting, App Store Connect API key for CI auth, and branch strategy (main → TestFlight, tags → App Store).
Red flag answer
I would use Xcode to build and upload manually. No CI/CD knowledge.
Cannot explain their state management pattern
Uses @State everywhere in SwiftUI or ViewModel in Android but cannot explain why or how the pattern breaks down at scale.
Has never submitted to the App Store directly
Always had someone else handle provisioning, certificates, and App Store Connect. Submission knowledge is essential for freelance work.
Optimises by rewriting -- not profiling
Suggests 'let us use a different framework' when faced with performance issues instead of opening Instruments or Android Studio Profiler.
Treats iOS and Android as the same
React Native or Flutter developers who cannot articulate key platform differences (Human Interface Guidelines vs Material Design, iOS Background Modes vs Android WorkManager).
No crash monitoring experience
Has shipped apps without Firebase Crashlytics, Sentry, or any crash monitoring. Apps without crash monitoring have unknown production quality.
Cannot write a UI test
Has never written XCUITest or Espresso tests. Mobile apps without automated UI tests require manual regression testing every release.
| Region | iOS (Swift) | Android (Kotlin) | React Native / Flutter |
|---|---|---|---|
| South Asia | $50-80/hr | $45-75/hr | $45-70/hr |
| Eastern Europe | $75-110/hr | $65-100/hr | $65-95/hr |
| Latin America | $60-90/hr | $55-85/hr | $55-80/hr |
| South-East Asia | $45-75/hr | $40-70/hr | $40-65/hr |
| Western Europe | $100-140/hr | $90-130/hr | $85-125/hr |
| North America | $120-180/hr | $110-160/hr | $100-150/hr |
All rates are engineer rates before the OTF 15% management fee. iOS engineers typically command a 10-15% premium over equivalent Android engineers in Western Europe and North America due to smaller talent pool. Rates shown are for mid-to-senior level (4-8 years).
Published engineer rates before the OTF 15% management fee. iOS engineers typically command a 10-15% premium over Android in Western markets due to smaller talent pool.
Junior (1-3 yrs)
Basic React Native / Flutter
Mid-level (3-7 yrs)
Solid iOS or Android production experience
Senior (7+ yrs)
Architecture depth, multi-platform
Junior (1-3 yrs)
Swift/Kotlin basics, junior Compose/SwiftUI
Mid-level (3-7 yrs)
Strong native iOS or Android depth
Senior (7+ yrs)
Platform architect, CI/CD owner
Junior (1-3 yrs)
React Native/Flutter entry-level
Mid-level (3-7 yrs)
Cross-platform specialists, some native
Senior (7+ yrs)
Full platform ownership
Junior (1-3 yrs)
Basic mobile dev, limited production
Mid-level (3-7 yrs)
React Native or Flutter mid-level
Senior (7+ yrs)
Native iOS or Android senior
Junior (1-3 yrs)
Computer science background, junior
Mid-level (3-7 yrs)
Production iOS or Android experience
Senior (7+ yrs)
Principal mobile engineer
Junior (1-3 yrs)
Entry-level with CS degree
Mid-level (3-7 yrs)
FAANG-adjacent iOS/Android
Senior (7+ yrs)
Staff/principal, platform lead
iOS SwiftUI + TCA architecture
+15-20%App Store + Play Store dual-platform
+10-20%React Native New Architecture (JSI)
+10-15%Mobile security (HIPAA/PCI/biometric)
+15-25%Mobile CI/CD platform ownership (Fastlane, Bitrise)
+10-20%ARKit / RealityKit / Vision Pro experience
+20-35%Premiums are applied to base regional rates. Vision Pro and spatial computing experience is extremely scarce -- expect the higher end of the premium range for any visionOS work.
Platform-specific vetting is the difference. A generic mobile developer from a broad marketplace may have shipped one app once. Our pool is verified against live production apps.
| Criterion | Open IT Freelancers | Toptal | Upwork | Staffing Agency |
|---|---|---|---|---|
| Vetting method | Live platform-specific technical screen: architecture, state management, App Store/Play Store submission | Algorithm & coding tests -- limited mobile-specific depth | Self-reported profile and portfolio only | CV review and sometimes a take-home task |
| Platform matching | Matched on iOS/Android/RN/Flutter with framework-level specificity | General 'mobile developer' category | Tag-based search, no framework validation | General mobile placement, rarely framework-specific |
| App Store submission experience verified | Yes -- live app links verified where possible | Not systematically verified | Not verified | CV claim only |
| Management fee | Flat 15% -- published in every contract | ~30-40% markup (undisclosed) | 10-20% platform fee on engineer | 25-40% markup, often undisclosed |
| Time to shortlist | 72 hours | 1-2 weeks | Immediate (unvetted pool) | 1-3 weeks |
| Matching fee | $0 | $0 (fee built into rates) | $0 (fee built into rates) | $0-5,000+ |
| Crash monitoring requirement | Required -- Crashlytics or Sentry setup included | Not managed | Not managed | Not typically enforced |
| Replacement guarantee | 14-day free replacement | Trial period (varies) | No guarantee | 30-90 days, often fee applies |
| iOS vs Android distinction | Separate pools, separate screening tracks | Limited platform distinction | No distinction enforced | Rarely distinguished |
| CI/CD pipeline expertise available | Yes -- mobile DevOps specialists in pool | Limited | Unvetted availability | Hard to source reliably |
| Weekly delivery reporting | Yes -- dedicated account manager | Not included | Not included | Sometimes, at extra cost |
A senior iOS engineer at $100/hr working 40 hrs/week for 16 weeks = $64,000 engineer cost.
Open IT Freelancers
$73,600
You pay $73,600 total
Toptal (est. 35%)
$86,400
~$12,800 more than OTF
Agency (est. 40%)
$89,600
~$16,000 more than OTF
Rates are illustrative. OTF fee is published -- others are estimates based on typical market markups.
Different industries have distinct mobile requirements. Tell us your industry and we match engineers with the right compliance, integration, and platform track record.
Mobile banking and payments require biometric authentication (Face ID, fingerprint), certificate pinning, PCI-DSS compliance, and real-time transaction updates via WebSocket or push notifications. iOS engineers with StoreKit 2 and secure enclave experience. Android engineers with Android Keystore and Google Pay integration. Zero tolerance for security vulnerabilities in this vertical.
Healthcare apps require HIPAA-compliant data handling, HealthKit and Apple Watch integration for iOS, Google Fit and Wear OS for Android, and accessibility compliance (WCAG 2.1 / iOS Accessibility / TalkBack). Telemedicine apps add video calling integration (WebRTC, Agora, Daily.co) and often require PHI encryption at rest and in transit.
E-commerce apps need deep-link routing, in-app purchase and subscription management (StoreKit 2, Google Play Billing 5), push notification campaigns, offline browsing with local caching, AR product preview (ARKit, SceneKit, Google ARCore), and Apple Pay / Google Pay checkout integration.
SaaS mobile apps typically extend web products. React Native and Flutter are popular here for codebase sharing with TypeScript teams. Key requirements: enterprise SSO (SAML, OAuth2), MDM/MAM compatibility, offline-first data sync, and complex form-heavy UI that performs well on business-grade Android devices.
Specific briefs get shortlisted fastest. These are examples of briefs we can match within 72 hours.
Swift, SwiftUI, TCA, Combine, Keychain, Face ID
Series B neobank. Existing UIKit app (2017, Objective-C) needs rewrite to SwiftUI with TCA architecture. Core features: account dashboard, P2P transfers, push notification for transactions, biometric auth, and Apple Pay. 6-month engagement. Must have prior fintech iOS experience and App Store submission ownership.
React Native (bare), TypeScript, HealthKit, Google Fit, Expo EAS
Health-tech startup. New app for iOS and Android connecting to wearables via HealthKit and Google Fit APIs. Push notifications for activity reminders, offline data storage with sync, and subscription via StoreKit 2 and Play Billing. HIPAA compliance required. Expo EAS Build for release pipeline. 4-month build, then maintenance retainer.
Kotlin, Jetpack Compose, Room, WorkManager, Google Maps, BLE
Logistics SaaS company. Android app for field engineers doing asset scanning via Bluetooth LE and barcode. Must work offline (warehouse signal is poor) with WorkManager sync. Jetpack Compose UI. Room DB for local storage. Google Maps integration for route navigation. Target: Android 10+ on Zebra and Samsung enterprise devices.
No fee to post. Platform-matched shortlist in 72 hours. Flat 15% if you hire.
Everything about hiring vetted iOS, Android, React Native, and Flutter developers through Open IT Freelancers.
Before You Hire
Written by our engineering team - no fluff, just the frameworks that work.
Developer rates by region, hidden cost breakdown, TCO comparison across DIY vs managed platforms, and a complete budgeting guide.
The 7-day vetting framework, technical interview questions, take-home test design, and red flags - built for non-technical founders.
Stage-by-stage decision framework for founders and CTOs. Cost, speed, and risk tradeoffs - with a clear verdict for each company type.
Platform-matched shortlist in 72 hours. No fee to post, no upfront cost. Flat 15% only when you hire.