TMS Outsource has been building custom mobile applications since 2014, working with startups, SaaS companies, and enterprise clients across fintech, healthcare, and e-commerce. With offices in Belgrade and Bucharest and 40+ engineers on staff, we deliver native iOS, native Android, and cross-platform React Native apps - from initial product discovery through App Store launch and ongoing support.
Three delivery paths. We help you choose based on performance requirements, budget, and target audience - not on what's easiest for us to sell.
When performance, platform integration, and App Store fit matter most. TMS builds native iOS apps in Swift and SwiftUI, with deep integration into iOS frameworks like Core Data, Core Animation, ARKit, and HealthKit. We handle the full lifecycle: architecture, development, testing, and App Store submission. Choose native iOS when your audience is iOS-dominant, when you need maximum performance, or when platform-specific features like widgets, Live Activities, or Apple Watch integration are part of the scope.
When device diversity, market reach, and Google Play integration are the priority. TMS builds native Android apps in Kotlin and Java, handling the full range of device sizes, hardware capabilities, and OS versions that the Android ecosystem demands. We manage the biggest challenge in Android development - making an app work flawlessly across a wide range of devices with varying screen dimensions and hardware - from the very beginning, not as an afterthought. Choose native Android when your audience skews Android, when you need deep Google services integration, or when device-specific features are required.
When one codebase, faster delivery, and lower cost matter more than platform-specific features. TMS builds cross-platform apps using React Native, sharing business logic and UI between iOS and Android while still delivering a native look and feel. This approach typically reduces development time and cost by 30–40% compared to building two native apps separately. Choose cross-platform when your budget is constrained, when you need to validate on both platforms quickly, or when your app's functionality doesn't require deep platform-specific APIs. Our business analysts will present the possibilities with pros and cons and help you choose the right path during the discovery phase.
Six service areas that cover the full mobile app lifecycle, from first prototype to App Store launch and beyond.
Custom iOS applications built in Swift and SwiftUI. Full integration with Apple frameworks, App Store submission, and ongoing compatibility updates for new iOS releases.
Custom Android applications built in Kotlin and Java. Device-wide compatibility testing, Google Play submission, and support for the full range of Android screen sizes and hardware.
React Native apps that share code across iOS and Android, reducing cost and delivery time by 30–40% while maintaining a native user experience on both platforms.
Our designers work alongside the development team to create intuitive, platform-appropriate interfaces that follow iOS Human Interface Guidelines and Material Design, validated with real users before development begins.
Every mobile release goes through structured QA: device testing across screen sizes, OS version coverage, regression suites, crash testing, and performance profiling before any build reaches the store.
Full App Store and Google Play submission: store listing creation, metadata, screenshots, review guideline compliance, submission, and rejection resolution. We manage the entire review cycle.
Outcomes, not features. Here's what working with TMS on mobile development actually delivers.
Ship iteratively, validate before you over-invest.
We deliver in iterative sprints, not a big-bang release. You get a working MVP in the App Store within 6–10 weeks, then iterate based on real user feedback. This means you validate your product hypothesis before committing the full budget, and every subsequent release is informed by actual usage data, not assumptions.
Eastern European engineering rates, no compromise on process.
TMS engineering rates are 40–60% below Western EU and US agency prices, with no compromise on delivery process, code quality, or communication. You get senior engineers, structured sprints, and transparent reporting - just at a rate that doesn't consume your entire runway before the product ships.
Discovery, design, development, QA, deployment, and support - same team.
The team that scopes your app is the team that designs it, builds it, tests it, ships it, and supports it. No handoffs between agencies, no lost context between phases, no "the previous team didn't document that." One accountable team across the entire lifecycle.
Source code, design assets, documentation - all yours.
All source code, design files, architecture documentation, and store listings belong to you from day one. No vendor lock-in, no hostage codebases, no surprise fees to access your own intellectual property. If you ever decide to move to an in-house team, the handover is clean and complete.
Domain experience that shortens the learning curve. We've shipped mobile apps in these verticals - we know the constraints before you explain them.
Mobile banking interfaces, payment integrations, KYC flows, and compliance-aware architecture. We understand PCI DSS requirements, PSD2 open banking APIs, and the audit trails fintech investors expect before funding the next round.
Patient-facing apps, telemedicine interfaces, and HIPAA-compliant data handling. We build mobile apps that integrate with EHR systems, handle sensitive health data securely, and meet App Store review requirements for health-related functionality.
Mobile companions to web-based SaaS platforms, offline-first data sync, push notification systems, and multi-tenant architecture on mobile. We understand the subscription model and build mobile experiences that drive retention, not just downloads.
Mobile shopping apps with payment gateway integration, inventory sync, personalized recommendations, and smooth checkout flows. We optimize for conversion on mobile, where the majority of e-commerce traffic now lives.
Property listing apps, virtual tour interfaces, tenant management portals, and real estate CRM mobile extensions. We build mobile tools that agents and buyers actually use in the field, not just polished demos.
Three engagement models. The right one depends on your team, your timeline, and how much control you want over the process.
Embed TMS engineers into your product team long-term. You get a dedicated iOS lead, Android engineer, or full mobile squad that works as an extension of your in-house team, attending your standups and reporting to your PM.
Fixed scope, fixed timeline, fixed delivery. Best when you have a clearly defined product spec and want a turnkey delivery from discovery through App Store launch. TMS owns the full process end to end.
Add specific skills to your existing team. Hire a senior iOS lead, a React Native engineer, or a mobile QA specialist without the recruitment timeline. Scaled up or down as your sprint cadence demands.
The mobile technologies we work with in production. If your stack isn't here, ask - we evaluate new frameworks when client requirements demand it.
Swift for application logic, SwiftUI for declarative UI, with UIKit where backward compatibility or complex custom views require it. We integrate Core Data, CloudKit, ARKit, HealthKit, WidgetKit, and Live Activities as project scope demands.
Kotlin as the primary language, with Java support for legacy codebases. Jetpack Compose for modern UI, Android Architecture Components for structure, and deep integration with Google Play Services, Firebase, and Material Design 3.
React Native with TypeScript for shared codebases. Native modules written in Swift and Kotlin when platform-specific functionality is required. Expo for rapid prototyping and EAS for over-the-air updates and managed builds.
Node.js, PHP/Symfony, and Python/Django for mobile backends. REST and GraphQL APIs, real-time WebSocket communication, push notification infrastructure, and authentication via OAuth 2.0 and JWT.
AWS, Google Cloud Platform, and Microsoft Azure for mobile backend hosting. CI/CD pipelines via GitHub Actions and Bitrise for automated builds, testing, and store deployment on every commit.
Fastlane for build automation, Sentry and Crashlytics for crash reporting, Firebase Analytics and Mixpanel for product analytics, and App Store Connect / Google Play Console API integration for release management.
A few products with significant mobile components. Full case studies available on the portfolio page.
Booking Platform · 1.5M+ installs
Appointment booking platform with a mobile interface serving 1.5M+ active installations. TMS handles the full stack, including the mobile experience.
View Case Study
Mobile-First SaaS · Remote Professionals
Mobile-first SaaS platform for remote professionals who need postal mail management on the go. Built with a mobile-first UX from the ground up.
View Case Study
Mobile App · Business Plan Validation
Mobile app for business plan validation, helping entrepreneurs test ideas before investing. Built natively with an offline-first data model.
View Case StudyTell us about your product idea, your timeline, or your existing codebase. We'll outline the right approach - native, cross-platform, or both.
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