Cross-Platform Productivity Mobile App

I need a complete mobile solution that runs smoothly on both iOS and Android and helps users be more productive throughout their day. Think of a clean, intuitive interface where people can create tasks, set reminders, track progress, and sync data seamlessly across their devices.

Here’s what I’m after:
• End-to-end development in Swift/SwiftUI and Kotlin or a proven cross-platform framework such as Flutter or React Native—whichever lets us ship quickly without sacrificing native-level performance.
• Account creation (email, Apple, Google), secure cloud sync, and basic offline support.
• Core screens: dashboard, task list with drag-and-drop reordering, calendar view, and simple analytics that show completed vs. pending work.
• Push notifications and in-app reminders.
• A lightweight admin panel or Firebase setup so I can manage feature flags and view usage stats.
• Clean, well-commented source code in Git plus TestFlight / Play Console builds for review.

Acceptance criteria will be a TestFlight link and an internal testing track on Google Play that match the spec, pass store guidelines, and include a brief README for handoff. I’m happy to iterate quickly—let me know your preferred toolset and timeline so we can get started.