Mobile App Development

Mobile app development that feels native, ships fast, and stays maintainable.SimplyRem builds iOS, Android, and React Native apps for product teams who care about how an app feels in the hand — the gesture latency, the spring of a transition, the calm of a well-considered empty state. Every engagement is led by a senior mobile engineer with shipped App Store and Play Store apps to their name. No outsourced subcontractors. No half-finished hand-offs.What we build

• Consumer iOS & Android apps — social, lifestyle, and on-demand apps designed to retain users past day-30.
• Field & logistics apps — offline-first React Native apps with WatermelonDB sync, on-device OCR, and Bluetooth peripheral integrations.
• Fintech & payments apps — KYC flows, biometrics, Apple Pay / Google Pay, PCI-aware architectures and hardened release pipelines.
• Companion apps for SaaS platforms — slim React Native or native apps that extend a web product into the user's pocket.
• Health, fitness & wellness apps — HealthKit, Google Fit, sensor integrations, and ATT/privacy compliance done properly.
• B2B field-service & enterprise apps — MDM-friendly builds, SSO, and CI/CD pipelines your IT team will sign off on.

Why teams choose our mobile app development services

• Native performance, even on React Native. 60fps animations with Reanimated, lazy-loaded screens, JSI-bridged modules where it counts.
• Senior-only delivery. A staff-level mobile engineer owns the project from kickoff to App Store submission — no juniors quietly billed at senior rates.
• Offline-first by default. Sync, conflict resolution, and graceful degradation are designed in from week one, not bolted on at the end.
• Design that respects each platform. iOS feels like iOS, Android feels like Android. Editorial-trained designers, motion designed alongside layout.
• Submission & review handled. We manage the App Store and Google Play review process — privacy nutrition labels, screenshots, App Privacy report, and rejection appeals included.
• Stay-on retainers. Most clients keep us on after launch to ship monthly releases, tune crash-free rates, and absorb new OS versions.

Native vs. React Native — what should you choose?We are agnostic, and we will tell you honestly. Native (Swift / Kotlin) is the right call when you depend on a rapidly-evolving platform API, push the GPU hard, or need every millisecond of battery. React Native is the right call when 70–90% of the codebase is product-shaped (forms, lists, navigation), you want one team shipping two platforms, and you can absorb a thin native module layer where the rendering or performance demands it. Most of our engagements over the last three years have been React Native with a small Swift/Kotlin module pocket — but we ship pure native builds whenever the brief points there.Our mobile app development process1. Discovery (1–2 weeks)We audit competitive apps, interview your users, and prototype the riskiest interactions in code — not Figma — so you know in week two whether the gesture, the animation, or the offline flow can actually be built the way it was sketched.2. Design & architecture (2–3 weeks)High-fidelity prototypes with motion specified frame-by-frame, plus a written architecture: data flow, sync strategy, navigation graph, deep-link map, analytics taxonomy, and a release plan covering beta, phased rollout, and rollback.3. Engineering in fortnightly incrementsYou see a working build on TestFlight and Play Internal Track every two weeks. Crash-free rate, install-success rate, and key user flows are reviewed at every sprint — not just at launch.4. Hardening & submissionAccessibility pass to WCAG 2.2 AA, App Store / Play Store review prep, privacy manifests, data safety forms, App Tracking Transparency handling, and a documented release runbook for your team.5. StewardshipMonthly retainers covering OS upgrades (iOS 18 → 19, Android 15 → 16), library churn, A/B tests, App Store optimisation, and the slow steady work of pushing crash-free rate from 99.4% to 99.9%.The mobile app development stack we ship

• Cross-platform: React Native (bare or Expo), TypeScript, Reanimated, Gesture Handler, Reanimated Skia for custom rendering.
• Native iOS: Swift 5/6, SwiftUI, Combine, Core Data, CloudKit, WidgetKit, App Intents.
• Native Android: Kotlin, Jetpack Compose, Room, WorkManager, Hilt, Material 3.
• Sync & data: WatermelonDB, Realm, SQLite, GraphQL with Apollo, offline mutation queues.
• Backend & infra: Node.js / Rust APIs, Firebase, Supabase, AWS Amplify when it earns its keep.
• Release engineering: Fastlane, EAS, GitHub Actions, Sentry, Firebase Crashlytics, Detox & Maestro for E2E.

Who we work withOur mobile app development clients are typically Series A–C startups with a senior product owner, or product teams inside established brands who need an outside studio to ship a flagship app the internal team cannot prioritise. We do our best work when the brief is ambitious — retention, performance, motion quality — and the people on the other side care about craft as much as we do.Engagement models & pricing

• Fixed-scope build — $90k–$400k+, three to six months. Best for a flagship iOS / Android launch or a single-platform pilot.
• Cross-platform sprint — $150k–$300k, four to five months. React Native build covering iOS and Android from one codebase.
• Embedded squad — monthly retainer, two to four engineers. Best for ongoing product evolution alongside your internal mobile team.
• Discovery sprint — $25k, two weeks. A de-risking exercise that produces a prototype, architecture, and a fixed quote.

We are booking new mobile engagements one quarter at a time. Tell us what you are building — we respond to every brief within one business day.