Need suggestions for Free, Open-source, privacy focused diary/Journaling app?

I am looking for a free and open-source software for writing diary or Journaling. My requirements are:-

1. Free, Open-source
2. Privacy focused (Maybe have End-to-end encryption)
3. Available on Android, Windows, MacOS, iOS and browser-based web app or extension
4. Provide option to store data either locally on device or cloud (Google drive, OneDrive etc.)
5. If data stored on cloud, be able to sync through all devices.

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