I am rebuilding the core experience of “Notdienst Assistent”, a mobile application that lets on-call emergency doctors in Germany create GOÄ invoices on the spot. The current prototype works, but its interface feels dated and slows doctors down. I now need a fresh, production-ready UI/UX concept that can be handed straight to Flutter developers for both Android and iOS. Scope of this phase • Onboarding • Profile setup • Dashboard • New-invoice flow (start → OCR card scan → add GOÄ codes → summary → PDF preview) • Saved-invoice and recipient lists • Basic settings What I’m looking for – A clean, modern, fast design system that respects German medical-billing norms. – Intuitive navigation that keeps cognitive load low when a doctor is standing at a patient’s bedside. – All screens delivered as Figma (or comparable) files, including components, typography, colour and spacing tokens built with Flutter’s Material 3 guidelines in mind. – Clickable prototype demonstrating the critical invoice flow. – Handoff notes covering animations, breakpoints and any custom widgets so the dev team can translate pixels to Dart without guesswork. Acceptance criteria 1. Each screen matches the agreed user journey and looks consistent across common Android and iOS breakpoints. 2. OCR scan and GOÄ-code selection states are clearly represented. 3. Design files include a reusable component library and style guide. 4. Prototype loads quickly and demonstrates the invoice flow end-to-end. If you have experience designing for healthcare, billing or any OCR-heavy workflow, mention it—those insights will be invaluable.