Mobile App Development Services
Mobile app development for iOS, Android, and cross-platform (React Native, Flutter). StepTo ships reliable, secure apps at 36-51% below Western rates.
Reviewed by Igor Gazivoda, Founder & CEO of StepTo · Published · Updated
StepTo builds high-performance mobile apps for iOS, Android, and cross-platform, with a relentless focus on user experience, reliability, and rapid iteration. Our nearshore engineering teams in Belgrade, Serbia work in your timezone (CET) and ship production-grade apps at 36-51% below typical Western European and US agency rates. We help enterprises, scale-ups, and founders launch apps that users keep on their home screen. App Store review cycles and OS updates never stop, so StepTo backs its mobile team with long-term continuity and 2.5+ years of average developer tenure to keep maintenance consistent long after launch. Looking to extend your own team instead? See our mobile app developer hiring guide.
What Mobile Solutions Does StepTo Deliver?
- Native iOS & Android, Swift and Kotlin apps that take full advantage of platform APIs, hardware, and performance for demanding, polished products.
- Cross-platform (React Native & Flutter), a single shared codebase when speed to market and a lean maintenance budget matter more than per-platform fine-tuning.
- Backend, APIs & cloud sync, REST/GraphQL services, real-time data, offline support, and push notifications on AWS, Google Cloud, or Firebase.
- App Store & Google Play launch, submission, review-guideline compliance, and the iterative fixes approval often requires.
- Post-launch analytics & growth, instrumentation, A/B testing, crash monitoring, and a roadmap of data-driven updates.
How Do We Build Mobile Apps?
- Discovery & scoping, we map the core user journeys, prioritise an MVP feature set, and choose native vs. cross-platform based on your real constraints.
- Design & prototyping, clickable prototypes validate flows before a line of production code is written.
- Two-week build sprints, demoable builds every sprint so you steer the product continuously, not at the end.
- QA & store launch, automated tests, device-farm runs, manual QA, and submission to both stores.
- Maintenance & iteration, OS-version upkeep, security patches, and ongoing feature development.
Why Choose StepTo?
- Senior engineers with shipped apps across fintech, healthcare, e-commerce, and logistics.
- CET-timezone collaboration, daily standups and real-time communication, not async-only handoffs.
- 36-51% cost savings versus Western European and US agencies at equivalent seniority.
- Security and compliance (GDPR, app-store data policies) built in from day one.
- Full IP ownership and clean, documented, handover-ready codebases.
Which Mobile Technologies Does StepTo Work With?
StepTo works across the four mainstream mobile stacks and recommends one per project rather than defaulting to a house favourite. The choice follows the performance, hardware-access, and maintenance constraints mapped in discovery.
- iOS: Swift and SwiftUI. Our iOS developers are assessed on Swift and SwiftUI before they reach a client; the iOS hiring guide sets out the skills we screen for.
- Android: Kotlin and Jetpack Compose. StepTo's Android engineers build Kotlin and Jetpack Compose apps in CET business hours; see the mobile hiring guide for how we vet them.
- React Native. Our React Native engineers are vetted on the New Architecture (JSI, the Fabric renderer, and TurboModules), native modules, and store releases. The React Native hiring guide also covers when an Expo-managed workflow fits and when a bare workflow is the better call.
- Flutter. We build on Flutter 3+ and Dart 3+, using Riverpod for most new projects and the Bloc pattern for applications with many state transitions. Platform channels and custom plugins cover native features such as biometric authentication, NFC, Bluetooth, and camera access. Details are in our Flutter hiring guide.
Where sharing business logic while keeping native UI matters most, the mobile developer hiring guide compares Kotlin Multiplatform against Flutter and React Native so you can weigh the trade-offs before committing.
How Does a Mobile Engagement Start?
The build lifecycle above runs inside a standard StepTo onboarding sequence, described in full on our process page. Discovery does not begin until an NDA, a data processing agreement, and IP assignment terms are signed.
- 60-minute discovery call. We come with specific questions about your product, stack, budget envelope, and timeline, and leave you with a preliminary view of team composition, engagement model fit, and indicative monthly cost.
- Candidates within five business days. We present three to five pre-vetted engineers matched to your platform and seniority needs. Each has already passed our three-stage screening: a technical challenge, a live coding interview, and a communication assessment.
- Two-week paid trial. The developer joins your communication channels and standups and completes a first sprint defined with your team lead. Equipment provisioning, system access, and legal agreements run in parallel on our side. Replacements during the trial are free.
- Full engagement. After a successful trial the team operates as part of your organisation, attending your sprint reviews and planning sessions and delivering against your roadmap. StepTo staffs mobile engagements from its standing bench of 15-20 engineers in Belgrade, which is why a team can usually be assembled in two to three weeks.
How Is a StepTo Mobile Team Composed and Managed?
A dedicated team starts from $13,500 per month for three engineers, typically a tech lead, a senior developer, and a mid-level developer. Whether additional seats go to a QA engineer, a backend developer, or a designer depends on the scope of the app and its services; we itemise the mix in the quote after discovery rather than selling a fixed bundle.
- Your standup, not a separate one. Augmented developers and dedicated teams join your daily standup and take part in your sprint reviews and retros as full team members. For dedicated teams we can also facilitate bi-weekly retros that include a StepTo account manager.
- Your tools and priorities. Tasks arrive through your project management tool, communication runs through your channels, and you control priorities, velocity, and release quality. StepTo's management role is the employment and HR side.
- CET working hours. Serbian engineers work in CET (UTC+1, CEST in summer), which gives full-day overlap with Western European clients and three to four hours of overlap with US East Coast teams for daily syncs.
- Scaling in weeks. Adding a mid-level generalist typically takes two to three weeks of lead time, and four to six weeks for senior engineers or specialists. Scaling down requires 30 days' written notice. You pay only for active team members; there is no retainer for bench capacity.
- Your code, unconditionally. Every developer signs a separate IP assignment agreement and an NDA, you have full access to all repositories from day one, and you retain code, documentation, configuration, and infrastructure scripts if the engagement ends for any reason.
Which Engagement Model Fits a Mobile Project?
StepTo offers the same three engagement models for mobile as for every other service, priced on our published rate card.
- Staff augmentation from $4,500 per month per developer, three-month minimum, weekly billing. Best when you have a product team and need an additional iOS, Android, React Native, or Flutter engineer inside it.
- Dedicated team from $13,500 per month, six-month engagement recommended but not imposed as a contractual minimum. Best for a product that will keep shipping after launch and needs continuity across OS releases.
- Fixed-scope project from $9,000 with milestone-based payments. Best for a defined MVP where scope, platforms, and acceptance criteria can be agreed up front.
Across all three, the rate you agree is the rate you are invoiced: it covers full-time availability, HR and payroll, Serbian employment compliance, office space, equipment, and account management, with no recruitment surcharges or management fees layered on top. Third-party services your app needs, such as cloud hosting or SaaS subscriptions, are passed through at cost. We invoice by SWIFT or SEPA in USD, EUR, or GBP, monthly on net-15 terms for dedicated teams and projects, and weekly on net-7 terms for staff augmentation.
What Do Clients Ask Before Launching a Mobile App?
Do you build both iOS and Android apps?
Yes. We build native iOS (Swift) and Android (Kotlin) apps, as well as cross-platform apps with React Native and Flutter when a single shared codebase is the better fit for budget and timeline. We recommend the approach based on your performance, hardware-access, and maintenance requirements rather than defaulting to one technology.
How much does it cost to build a mobile app with StepTo?
Most mobile MVPs fall between $30,000 and $80,000 depending on scope, number of platforms, and backend complexity. Because our engineers are based in Serbia, blended rates run 36-51% below comparable Western European or US agencies for the same seniority. See our pricing page for current rate bands.
Can you handle backend, APIs, and cloud integration?
Yes, StepTo delivers the backend as well as the app. We deliver the full stack, REST/GraphQL APIs, real-time sync, push notifications, and cloud infrastructure on AWS, Google Cloud, or Firebase, so the app and its services are built and maintained by one accountable team.
How do you ensure app quality and store approval?
Every release goes through automated unit and UI testing, device-farm testing across real hardware, and manual QA. We also handle App Store and Google Play submission, review guidelines, and the post-launch fixes that approval often requires.
How long does it take to launch a mobile app?
A focused MVP typically reaches the stores in 8-16 weeks. We work in two-week sprints with demoable builds throughout, so you see and steer progress continuously instead of waiting for a single final delivery.
Do you provide post-launch support and updates?
Yes. We offer ongoing maintenance covering OS-version updates, security patches, analytics-driven improvements, and new feature development under a dedicated-team or retainer arrangement.
How quickly can a mobile team start work?
A StepTo team is typically selected and under contract within two to three weeks of the first conversation and reaches full delivery productivity by week six. When you already have a clear brief, a defined stack, and time for a one-hour discovery call, onboarding can compress to as little as ten business days, and for urgent needs we often have pre-vetted engineers available immediately from our active talent pool. Senior specialists take longer to source than mid-level generalists, and we flag that early rather than mid-search.
Who manages the mobile developers day to day?
You do, by design. StepTo engineers work under the direct management of your product and engineering leads, receive tasks through your project management tools (Jira, Linear, Trello, or whichever you use), communicate through your channels (Slack, Teams, email), and report progress in your standups. StepTo handles the employment side: contracts, payroll, performance conversations, and retention. For dedicated teams, the engagement may include a tech lead who takes on some day-to-day coordination, but they still report to your overall product or engineering leadership.
Which engagement models are available for mobile development?
Three. Staff augmentation adds individual iOS, Android, React Native, or Flutter engineers to your existing squad from $4,500 per month per developer, with a three-month minimum and weekly billing. A dedicated team starts from $13,500 per month for three engineers, with a six-month term recommended but not imposed as a contractual minimum. Fixed-scope project delivery starts from $9,000 with milestone-based payments and suits a defined MVP. Hourly equivalents run $25-85 depending on seniority; see the pricing page for the full rate card.
What happens if a developer is not the right fit?
Replacements are free within the first 30 days: if an engineer is not working out, you can request one at no cost and with no questions asked. For issues that emerge later, a formal performance improvement process applies, facilitated by your StepTo account manager. If improvement does not occur, we source a replacement and manage the handover to minimise disruption to your release schedule. Our pre-engagement vetting means this is rare, but we treat it as our highest-priority obligation when it happens.
