NotePlanN
NotePlan

Face ID/Touch ID Protection on iOS

Just a layer of a bit of security for your really personal data (like diary), not to encrypt everything. Many apps have it these days. Perhaps it's easy to plug-in.
PendingPending

Looks indeed very useful for confidentiality where NotePlan may be used for sensitive professional activity.

Yeah. This looks like a very useful feature for users!

These things should be end to end encrypted but this protection for macOS (and iOS) is a must and everyone should vote this up.

+1, also on macOS would be greatly appreciated!