OmniTask

• 

  App Screenshot demonstrate home,voice recording and plans screen

Inspiration

I use an Android phone but do most of my work on a Mac. That setup sounds normal, but it breaks almost every reminder app.

Apple Reminders works well on macOS but is unusable on Android. Google Tasks works on Android but feels limited and poorly designed on desktop. Most good reminder apps force you to stay inside one ecosystem.

I kept missing reminders not because I forgot, but because my tools didn’t stay in sync. That frustration is what inspired OmniTask — a reminder app built for people who don’t want to pick sides.

What it does

OmniTask is an offline-first, cross-platform reminder app that works across Android, iOS, macOS, and Web.

It allows users to: 1-Create reminders that work even without internet 2-Set recurring reminders with flexible schedules 3-Use custom snooze options directly from notifications 4-Receive different types of notifications based on urgency 5-Keep reminders automatically synced across devices

Notifications are treated as the main interface, so users can manage tasks without constantly opening the app.

How we built it

OmniTask is built using Flutter to maintain a single codebase while adapting the UI to feel native on each platform.

All reminder data is stored locally using SQLite, making the app fully functional offline. Sync is handled in the background using a cloud backend so data updates automatically when connectivity is available.

Special care was taken to design a robust notification system that supports actions like snooze and complete directly from the notification across platforms.

Challenges we ran into

The biggest challenge was designing a notification architecture that behaves consistently across platforms while still respecting platform limitations.

Handling offline-first sync without causing conflicts or user-visible errors was another major challenge. Ensuring reminders always felt reliable — even with poor connectivity — required careful state management.

Balancing platform-specific UI details while using a shared codebase was also a constant tradeoff.

Accomplishments that we're proud of

1-A fully offline-first reminder system that never blocks the user 2-Reliable background sync across devices 3-Actionable notifications with custom snoozing 4-A clean, platform-aware UI that feels intentional 5-A working foundation that can scale beyond a hackathon project

What we learned

1-This project reinforced that cross-platform apps don’t have to feel generic. 2-By prioritizing offline reliability, thoughtful notifications, and platform-specific design choices, it’s possible to build a tool that feels dependable and polished across very different ecosystems. 3-We also learned the importance of treating notifications as a core product feature rather than an afterthought.

What's next for OmniTask

1-Next, we plan to:Improve natural-language reminder input 2-Add more advanced recurring and smart reminder rules 3-Expand widget customization 4-Polish accessibility and performance 5-Prepare stable public releases for mobile and desktop platforms

OmniTask is meant to grow into a long-term tool, not just a hackathon demo.

Built With

• android
• dart
• drift)
• flutter
• ios
• macos
• riverpod
• sqlite
• supabase