Senior Mobile App Developer
Senior Mobile App Developer for Existing Apps, MVPs, Rebuilds, and Launches
Build and improve native iOS and Android apps in Swift and Kotlin. Work directly with a senior developer who uses AI to accelerate implementation across platforms, with hands-on architecture, backend integration, testing, and release support.
For Buyers Who Need the Mobile App to Actually Hold Together
Native development is my default for new iOS and Android work. AI helps me carry functionality between Swift and Kotlin quickly, with manual testing and adjustment alongside AI-assisted automated smoke tests. Shared behavior still needs deliberate architecture, backend contracts, and verification on both platforms. Existing React Native or Unity apps are assessed on their own merits, not treated as automatic rewrite candidates. Read why I prefer native mobile development in the AI era.
New mobile MVP
Build a focused native iOS or Android first version, or plan both platforms around shared product requirements, clear scope, and a realistic release path.
App rebuild
Assess what should be retained, repaired, or replaced. Plan a rebuild around the required behavior, existing users, backend compatibility, and a staged release.
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
Creator social app
Stabilized an early SwiftUI codebase and added media handling, curated feeds, notifications, Firebase workflows, and a React analytics dashboard.
View ProofMobile and backend systems
Experience spans native iOS and Android, React Native/Expo, offline workflows, connected devices, authentication, and the APIs behind mobile products.
View ProofApp portfolio
Explore mobile work across consumer, creator, education, and interactive products, with links to existing project material.
View ProofSenior 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.
Android, Kotlin, and platform parity
Build native Android functionality in Kotlin and carry features between iOS and Android with AI assistance, shared API contracts, and platform-specific verification.
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.
Questions About Your Mobile Project
Can you take over our unfinished app?
Yes. Start with a review of the code, backend, build process, and store accounts. Establish what works on each target device, what blocks release, and which features remain unfinished. Bill can then scope stabilization and continued development around a specific release goal. The WeatherSats AR example above shows documented midstream work.
Should we rebuild or repair the app?
Assess the failures before choosing a framework or a rewrite. Repair may fit when the product's architecture still supports its requirements; replacement may be justified when a platform constraint or structural problem blocks them. Include existing users, stored data, backend contracts, and store distribution in the decision.
Do we have to move to native iOS and Android?
No. Swift and Kotlin are Bill's default for new mobile work, but an existing React Native or Unity product is assessed on its own merits. Required device features, current code quality, team skills, and maintenance needs determine whether to keep the stack or change it.
Can you handle the backend and release too?
Yes, within the agreed scope. Mobile work can include authentication, APIs, storage, notifications, admin tools, and release preparation. Agree who owns developer accounts, device testing, submission, and post-launch support; store review is a separate step from completing the implementation.
Related Services
iOS App Development Consultant
Native iOS consulting for SwiftUI apps, Firebase systems, and App Store launches.
View ServiceReact Native Consultant
Cross-platform consulting for React Native apps, MVPs, and rescue projects.
View ServiceAI Integration Consultant
AI feature integration for mobile apps, workflows, internal tools, and backend systems.
View ServiceHave a Mobile App, MVP, or Existing Codebase That Needs Senior Help?
Describe the app, target platforms, what already works, and what blocks the next release. Include the backend, important device features, timing, and budget context. Start with a project description; arrange code and account access separately.
Discuss Your Mobile App