I need a production-ready mobile app, similar in workflow to the iFing scanner, that can capture fingerprints and instantly convert the images to high-quality greyscale. The build has to run smoothly on both Android and iOS from a single codebase or two native projects—whichever you feel ensures the best speed and image fidelity. Core workflow • Launch the camera or fingerprint sensor, guide the user to place a finger, and grab a clear print. • Process that print on-device, converting it to greyscale with minimal noise and consistent contrast. • Offer a simple toggle so the user (or my back-office API) can decide whether the processed image is saved only on the device or immediately pushed to a server endpoint I will supply later. • When the server option is chosen, the app must handle secure transfer (TLS) and show basic upload status. I will provide the server credentials and expected JSON payload format; you handle the local SQLite / secure file store for on-device saves. All source code, build scripts, and a concise setup guide are part of the hand-off, together with a short note on any third-party libraries you integrated for image processing (e.g. OpenCV, ML Kit, Core Image). Acceptance criteria 1. Fingerprint capture and greyscale conversion complete in under three seconds on mid-range devices. 2. Local save path and server upload both verified through a quick demo session. 3. No crashes or major UI glitches on the latest two OS versions of Android and iOS. If you specialise in Flutter, React Native, Kotlin/Swift, or another mobile stack that can meet these requirements, let me know which you prefer and why.