I am trying out a new program for, writing, note taking, outlining, and many other text based operations. I was drawn to it because at its core are flat text files stored in .md format (Markdown). This allows zero lock in as .md files can be read by any text editor.
It has a user extendable architecture and many folks are writing add-ons for it.
Obsidian is the private and flexible writing app.
For all platforms, including Linux, and phones.
It is a Java script framework for making apps.
That sort of look native, but ain't.
Basically a program that runs in a web browser.