Educational iOS & Android App

I need an end-to-end build of a mobile educational app that runs natively on both iOS and Android. The goal is to deliver engaging learning content in a clean, intuitive interface while tracking user progress and performance.

The core experience should let students browse structured lessons, watch or read the material, take short quizzes, and view feedback immediately. A lightweight sign-up flow with social or email login is enough for launch, but the architecture should leave room for future features such as in-app discussion or gamified rewards.

Deliverables
• UX/UI mock-ups (Figma or Sketch) approved before coding
• Production-ready iOS (Swift/SwiftUI) and Android (Kotlin/Jetpack) builds, each passing App Store & Play Store review
• Shared code where sensible (e.g., via Kotlin Multiplatform, Flutter, or React Native) as long as final binaries feel native
• Basic admin dashboard or JSON-based backend to add/edit lessons, questions, and answer keys
• Source code in a Git repository with clear README and setup instructions

Acceptance Criteria
• Smooth performance on recent iOS and Android versions
• Lesson completion and quiz scores persist locally and sync to the backend on login
• UI matches approved designs within a 2 pt / 2 dp tolerance
• No critical crashes during a 30-minute exploratory test on real devices

Please include a short note on your preferred tech stack and any relevant educational or mobile projects you have shipped.