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... (Budget: $30 - $250 USD, Jobs: Android, Android App Development, Flutter, iOS Development, iPhone, Mobile App Development, PhoneGap, React Native)