I am using Standard Notes currently but I don’t want to pay 10$/month anymore.
** Edit: Guys thank you all for your suggestions. Unfortunately I couldn’t find a one-size-fits-all approach like Google Keep or Apple Notes. I realized that we really dont have much choice as an open source community.
I decided to close my Standard Notes account and started using Gnome Text Editor (it does more than you think) with Syncthing. I am using Markor on my Android end. But it is not really a reliable solution since Syncthing consumes more battery than your average notes app and its GTK client is cumbersome. So even though my quest will continue, I am done for now. **
https://f-droid.org/packages/org.secuso.privacyfriendlynotes
EteSync Notes - End-to-end Encrypted Notes (Secure, end-to-end encrypted, and privacy respecting note taking.) - https://f-droid.org/packages/com.etesync.notes
SilentNotes (Note taking app with optional end-to-end encrypted sync to your PC.) - https://f-droid.org/packages/ch.martinstoeckli.silentnotes
deleted by creator
if you open it in fdroid it should work
i cannot find the SilentNotes app on fdroid. the link gives a 404
deleted by creator