Senior Mobile App Developer

Senior Mobile App Developer for Existing Apps, MVPs, Rebuilds, and Launches

Build, stabilize, or scale mobile software with senior engineering across iOS, Android, React Native, SwiftUI, Kotlin, Unity/C#, Firebase, backend APIs, BLE, WatchOS, AI features, App Store and Google Play releases, and product architecture.

Senior mobile app developer for iOS Android and React Native products

For Buyers Who Need the Mobile App to Actually Hold Together

A mobile app is rarely just screens. It usually includes authentication, backend data, permissions, notifications, payments, media, analytics, admin workflows, app store releases, and long-term maintenance. This page is for buyers who need a senior developer involved directly in those decisions and in the implementation.

New mobile MVP

Build a focused first version for iOS, Android, React Native, or Unity with clear scope and a realistic release path.

App rebuild

Replace a fragile, abandoned, or unfinished app with a cleaner implementation and better technical foundation.

Existing app stabilization

Fix crashes, state bugs, performance issues, Firebase problems, technical debt, and release blockers.

Firebase-backed mobile apps

Use Firebase Auth, Firestore, Storage, Cloud Functions, push notifications, security rules, analytics, and admin workflows with better structure.

AI-enabled mobile features

Add AI workflows, summaries, search, assistants, or automation features inside real mobile products.

Launch and iteration

Support TestFlight, App Store release, crash fixes, user feedback, and post-launch feature work.

Relevant Mobile Proof Points

New Digital Commune

Delivered a SwiftUI/Firebase social app for creators with AVKit/Nuke media handling, GIF previews, curated feeds, push notifications, Cloud Functions, BigQuery analytics, and a React dashboard.

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NASA WeatherSats AR

Stabilized and shipped a cross-platform iOS/Android AR app experience built with Unity and AR Foundation for NASA's STEM program.

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React Native and native breadth

Delivered React Native/Expo, SwiftUI, Kotlin, Flutter, BLE, WatchOS/HealthKit, and native share-extension work across field-service, science, fitness, hardware, and media apps.

Production app takeover

Handled updates and rescue work for apps including Cellf Defense, Stupid Simple Macro Tracker, SmoothSpeak, WaterSprout, Pickleball Match, and other client codebases.

App Store portfolio

Portfolio includes Eureka Canvas, Planet XR, ModaVision, CRAFT, Soul and Form, WeatherSats AR, and other published or TestFlight-distributed mobile projects.

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Senior Mobile App Development Services

iOS, SwiftUI, and Apple frameworks

Build native iOS apps with SwiftUI, UIKit, Combine, StoreKit, AVKit, MapKit, WatchKit, HealthKit, Vision, App Store readiness, and maintainable structure.

React Native and cross-platform

Use React Native, Expo, TypeScript, Kotlin, Flutter, or Unity when it fits the product, and avoid cross-platform shortcuts when native control matters more.

Backend and Firebase

Connect mobile features to Firebase, custom APIs, storage, authentication, notifications, dashboards, and operational systems.

Technical rescue

Review existing mobile codebases and find the shortest practical path to a stable app, release, or rebuild.

Common Buyer Questions

Native or React Native?

The right answer depends on features, budget, timeline, team, performance needs, and long-term maintenance.

Can you take over an app?

Yes. The usual first step is a codebase, backend, architecture, and release-process review.

Can you build the backend too?

Yes. Mobile work often includes Firebase, Node.js APIs, storage, notifications, admin tools, and data modeling.

Related Services

iOS App Development Consultant

Native iOS consulting for SwiftUI apps, Firebase systems, and App Store launches.

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React Native Consultant

Cross-platform consulting for React Native apps, MVPs, and rescue projects.

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AI Integration Consultant

AI feature integration for mobile apps, workflows, internal tools, and backend systems.

View Service

Have a Mobile App, MVP, or Existing Codebase That Needs Senior Help?

Contact me about an iOS app, Android app, React Native app, Firebase-backed MVP, AI mobile feature, app rebuild, or technical rescue project.

Contact Me About Your Mobile App
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What Clients Say

Verified reviews from real projects

“Amazing in communication.”

⭐⭐⭐⭐⭐

Client · iOS App (Swift & Firebase)

“Went above and beyond.”

⭐⭐⭐⭐⭐

Client · Firebase Integration Revamp

“It was great working with Bill! Very pleasant and knowledgeable.”

⭐⭐⭐⭐⭐

Client · Language Learning App