This project delivers a mid-fidelity frontend prototype for a digital-health research app built with Flutter and Dart. The goal is strictly UI/UX validation; there is no backend integration or persistent data storage in this phase. The build must run smoothly on both Android and iOS. I will supply the design guidelines that drive color, typography, spacing, and component behaviour, and expect you to translate them into accessible, responsive Flutter widgets. Key screens include the onboarding series, an email-and-password sign-in flow (UI only), multi-step questionnaire and survey views, plus reminder and notification concepts. Smooth navigation, basic state handling, and adherence to accessibility best practices are all part of the brief. Deliverables • A runnable Flutter prototype targeting Android and iOS • Clean, well-commented source code in a Git repository • Straightforward build/run instructions that let me compile and install the app locally No production services, databases, or external APIs are needed—everything remains front-end only so I can validate look and feel with test participants.