I need a cross-platform mobile app that lets field operators working in remote areas calculate equipment depths and lengths in real time even when they have zero connectivity. The build has to run smoothly on both iOS and Android, so feel free to reach for Flutter, React Native, or any other framework you trust that can compile to both stores. Key requirements • All core calculations must work completely offline, with local data persistence and automatic background sync once a signal is regained. • Operators will interact through a touch interface most of the time, but I also want basic voice commands (start, stop, save, cancel, etc.) so they can keep their gloves on. • Depth-and-length formulas should update live on screen as the equipment extends or retracts; no manual refreshes. • The UI has to stay lightweight and readable under harsh sunlight. Deliverables 1. Production-ready iOS and Android builds. 2. Source code with clear comments and a brief setup guide. 3. Simple data export-import mechanism (JSON/CSV) for supervisors. 4. Short demo video proving offline usage and later sync. Acceptance criteria • Calculations remain accurate to within 0.5 % when compared with known measurements. • No crashes or data loss after 48 hours of continuous offline use. • Successful sync of at least 500 stored records once connectivity returns. If something in the workflow feels unclear, let’s discuss it early so the first iteration already heads in the right direction.