Personal Productivity App for iOS/Android

I’m looking for a developer who can craft a simple, reliable productivity app that I’ll use myself on both iOS and Android devices. The core of the project is straightforward: combine a clean note-taking workspace with seamless calendar integration so my reminders, events, and quick thoughts live in one place.

Here’s what matters most to me:
• A fluid note editor that supports rich text and quick search.
• Two-way sync with the device’s native calendars so events created in the app appear in Apple Calendar and Google Calendar—and vice-versa—without extra taps.
• An uncluttered UI that feels at home on both platforms, preferably built with a cross-platform tool such as Flutter or React Native for easier maintenance (open to your recommendation).
• Local data storage with optional cloud backup so I never lose my notes or events.
• Delivery of the full source code plus build instructions, so I can generate future private builds myself.

Once I can install and run a test build on my personal iPhone and Android phone, we’ll walk through any final tweaks before you hand over the final signed builds and documentation. Looking forward to seeing how you’d bring this focused little productivity boost to life.