I need a robust cross‑platform mobile application (single Flutter codebase) that talks directly to a Raspberry Pi–based device over Wi‑Fi/Bluetooth and walks users through a short diagnostic workflow. The same build must run smoothly on both iOS and Android. Developer requirements: Strong experience with Flutter (Dart) for iOS and Android. Practical experience integrating with Raspberry Pi over Wi‑Fi and/or Bluetooth using standard protocols. Comfortable building REST APIs in PHP with a MySQL database on shared hosting (Hostinger Business plan). YOU MUST HAVE ACCESS TO A RASPBERRY PI FOR TESTING and be able to demonstrate the end‑to‑end flow. Reference APK (current Android build for reference only): APK LINK: https://drive.google.com/file/d/1hDFEqTvzIQ5eCl6xs-xBfjX9-bnV4K0_/view?usp=sharing Please note this is a client project, so provide realistic, rational quotations. Over‑inflated bids will be ignored. App flow (final desired behaviour): Screen 1 – Discover, pair and stay connected to the Raspberry Pi over Wi‑Fi/Bluetooth. Screen 2 – Present a short questionnaire; store responses locally and/or in the backend (queue locally if offline, sync when online). Screen 3 – After device trigger, show captured images; allow capturing and previewing multiple image sets with “retake” and “confirm” for each of the 3 images. Screen 4 – On the next device trigger, display sensor values streamed from the Raspberry Pi in (near) real time in a clean, optimized layout. Screen 5 – Result / detection screen: show detection grade, yes/no classification and a clear summary. Screen 6 – Ensure everything from screens 2–5 (questionnaire + images + sensor data + result) is reliably uploaded to the online backend (MySQL), with visible progress and success/fail feedback. Backend / Tech Stack Requirements (very important): FIRST PREFERENCE is that the backend is deployable on an existing Hostinger Business web hosting plan with MySQL (shared hosting, no Node.js, no VPS). Tech stack must respect these constraints: Mobile app: Flutter (Dart) for iOS and Android. Backend (must work on Hostinger Business plan): REST API over HTTPS. PHP 8.x (plain PHP or a lightweight PHP micro‑framework such as Slim/Lumen; NO Node.js, NO Python/FastAPI). MySQL database (schema to be designed by you) for: Questionnaire responses Image metadata (paths, timestamps, sample IDs) Sensor readings Result / detection data File storage on the same Hostinger account (e.g., /public_html/uploads/...) for image files, with proper file naming and mapping to DB records. Communication: Flutter app → PHP REST API (JSON + multipart/form-data for images). Raspberry Pi → Flutter (local network) for triggers, images and sensor data (the Pi already sends its data when connected; you will consume and forward/store it). Backend expectations: Design clear REST endpoints, e.g.: POST /api/v1/samples (3 images + metadata + questionnaire + sensor data) GET /api/v1/samples/{id} GET /api/v1/samples?page=…&limit=… Design MySQL schema and relationships for samples, images, questionnaire answers and sensor readings. Implement basic secure token/API key flow for the app to talk to the backend (no heavy auth system needed initially, but should not be completely open). All code must be compatible with standard Hostinger Business PHP + MySQL shared hosting deployment (no Node.js, no custom daemons, no root access). Deliverables: Production‑ready Flutter source code (Android + iOS) with: Device discovery / pairing with Raspberry Pi. Questionnaire screen (screen 2). Multi‑image capture and confirmation flow (screen 3). Live sensor display screen (screen 4). Result and upload / status screen (screen 5/6). Offline caching and retry logic for uploads is a plus. Backend code: PHP 8.x REST API, structured for deployment on Hostinger Business. MySQL schema (DDL scripts) and any migration instructions. Clear configuration/env instructions (e.g., sample config.php or .env values) for Hostinger deployment. Documentation: Brief API documentation (endpoints, request/response formats, status codes). Build and deployment instructions for: Flutter Android and iOS builds. Deploying PHP + MySQL backend on Hostinger Business. Short video or detailed screenshots showing the full end‑to‑end workflow: Device pairing Questionnaire Image capture/confirm Sensor streaming Data upload Result screen Data visible in backend DB/UI Key success criteria: Reliable and stable device pairing with Raspberry Pi (Wi‑Fi/Bluetooth as per current APK behaviour). Instant, smooth image preview and “retake” flow for three images per sample. Lossless, reliable data upload to the PHP/MySQL backend on Hostinger (including retry if interrupted). Clean, intuitive UI with identical behaviour on both platforms (Android and iOS). Backend code that can be dropped onto Hostinger Business (PHP + MySQL) and work without requiring VPS/Node.js. If this matches your skill set (Flutter + Raspberry Pi + PHP/MySQL REST backend on shared hosting) and you have access to a Raspberry Pi for testing, please share: Relevant past work (Flutter + hardware / IoT / RPi, and PHP REST APIs). A rough timeline for: UI adjustments Backend implementation Integration and testing. Any suggestions to further optimize the flow within a Hostinger Business environment.