Client Task Prioritization App

I’m looking to have a lightweight mobile application built that I can open on either my iPhone or an Android device, hand to a client, and let them score the potential impact of NOT completing particular tasks. They will simply swipe through each item and choose a value from 1 – 5 on a clean, minimalistic scale. As soon as they finish, the app automatically sorts every task from highest to lowest risk and shows the ordered list on screen.

Core workflow
• Enter or import a set of tasks.
• Client assigns an impact rating (1–5) to each item.
• The app instantly reorders the list by highest average score.
• I can save, edit, or export that prioritized list (CSV, PDF, or share sheet).

Key requirements
• Native-feeling performance on both iOS and Android—Flutter, React Native, Kotlin Multiplatform or similar cross-platform stack is fine as long as one codebase serves both stores.
• Extremely simple, distraction-free UI: white background, single font family, clear buttons, no extra graphics.
• All logic runs offline; cloud sync or login may be added later but is not essential for this build.
• Source code, build instructions, and store-ready packages delivered at project hand-off.

Acceptance criteria
– I can add at least 100 tasks, assign ratings, and receive a correctly sorted list in under five seconds on a recent mid-range phone.
– Usability passes a brief test with three non-technical users (they must be able to complete an assessment without guidance).
– Codebase compiles cleanly in the latest stable Xcode and Android Studio.

Let me know which framework you prefer, any prior work that shows a similarly clean interface, and your estimated timeline for TestFlight/Play testing.