Native iOS Developer (Swift + Capacitor) — Background Location Tracking & Photo Metadata Scanning

This is a private/invite-only listing. Please keep the details of this project confidential and do not share this posting outside of Upwork. ABOUT THE PROJECT I run an existing consumer iOS app with a fully built frontend (React/TypeScript + Capacitor + Supabase). It currently runs on demo data. I need an experienced native iOS engineer to build two core features and polish the existing UI to a premium finish. Full product details, branding, and repo access will be shared directly once we're in contact and an NDA is signed — this listing covers the technical scope only. This is NOT just backend plumbing — I need someone who takes pride in shipping something that looks and feels elevated, not just functional. SCOPE OF WORK Background location tracking Build a native CoreLocation-based system that passively classifies movement state (stationary, ground transit, high-speed/air transit) in the background — battery-efficient, App Store compliant, and reliable enough to reconstruct a user's activity history without manual input. (I have a working JS prototype of the detection logic as a functional reference — you'll replace it with a proper native implementation.) Photo library metadata import Build a PhotoKit-based scanner that reads geotagged photos from the user's library and retroactively reconstructs historical location/date data from photo metadata. UI/UX elevation pass Go through the existing screens (dashboard, stats visualizations, activity timeline, onboarding) and tighten up the details: spacing, typography, transitions/animations, dark theme consistency, and general "premium feel" polish. You're not redesigning from scratch — you're taking a strong existing design and making it feel finished. REQUIREMENTS Strong Swift/iOS experience, specifically CoreLocation background modes and PhotoKit Experience building or integrating native Capacitor plugins (bridging Swift to a React/TypeScript frontend) A genuine eye for UI/UX — please include examples of apps where you've done both native engineering and visual polish, not just one or the other Comfortable working in an existing React/TypeScript/Capacitor/Supabase codebase Understanding of App Store review requirements around location permissions and background tracking NON-NEGOTIABLE No third-party location or tracking SDKs (e.g., no Transistorsoft/BGGeo) — custom native code only Full work-for-hire: 100% of code and IP transfers to me on payment, no retained rights NDA and IP-assignment agreement (simple, one-page) signed before repo access or product specifics are shared BUDGET & STRUCTURE Fixed price, paid in milestones as each deliverable is completed and approved (Upwork escrow protects both sides). Sequenced so the highest-risk technical work is validated early, before committing to the full scope — total across all milestones is capped around $3,000–$5,500. Background location classification prototype — a working proof of concept (can be a standalone test harness, doesn't need to be wired into the app yet) demonstrating reliable CoreLocation-based detection of stationary / driving / flying states in the background, with reasonable battery behavior over real-world testing — $600–$900 Full Capacitor/Swift plugin integration — wiring the validated classifier into the app, exposing it to the React/TypeScript frontend, proper background modes and permission handling for App Store compliance — $700–$1,000 Photo library EXIF scanning + trip reconstruction — $900–$1,500 UI/UX polish pass across existing screens — $700–$1,200 Final QA, bug fixes, TestFlight-ready build — $300–$500 Milestone 1 is the proving ground — if the classifier is accurate and battery-efficient, we move straight into the rest. Potential for ongoing work as the app moves toward App Store launch. TIMELINE Looking to start within the next couple weeks, with a working TestFlight build in 4–6 weeks. Open to discussing based on your availability. TO APPLY Please include: 2–3 examples of shipped iOS apps where you handled both native location/photo features AND UI polish A short note on how you'd approach battery-efficient background location tracking on iOS Your estimated hours for the three scope items above Confirmation you're willing to sign an NDA before receiving further project details