Cross-Platform Field Surveyor App

I need a mobile application that onsite surveyors can open, snap a picture of a building element, jot a quick note, and trust that everything—including location data—gets saved even when they are underground or out of range. Once a signal returns, the app should quietly sync to the server without the user having to think about it.

Core workflow
1. Launch the app on either an iPhone or an Android handset.
2. Capture a photo, draw or type annotations directly on that image, and enter a description in a clean, clutter-free form.
3. The app automatically records latitude and longitude at the moment the shutter clicks.
4. If connectivity is poor, all data—images, annotations, text and coordinates—stays on the device until a connection is detected, then syncs in the background.

Essential deliverables
• Production-ready iOS and Android builds (TestFlight / APK)
• PDF format in a presentation approach
• Simple cloud back-end or API endpoint for secure data sync
• Basic UI/UX documentation so future updates remain consistent

Acceptance criteria
• Photo, annotation, description and geo-tag must save locally in <2 seconds on mid-range devices.
• Offline capture and automatic background sync demonstrated in airplane-mode test.
• Data appears correctly in the back-end with image, text and coordinates linked.

If the stack you prefer is Flutter, React Native, Kotlin Multiplatform, or something similar, feel free to propose it—cross-platform parity and smooth offline handling are what matter most.