WriteRoom - For Mac users to write without distractions. WriteRoom is a full screen writing environment.
iA Writer - Minimal Design, Maximum Focus
Typora - A minimal Markdown reading & writing app.
FocusWriter - FocusWriter is a fullscreen, distraction-free word processor designed to immerse you as much as...
WordGrinder - WordGrinder is a word processor for processing words. It is not WYSIWYG. It is not point and click.
Joplin - Joplin is a free, open source note taking and to-do application, which can handle a large number of notes organised into notebooks. The notes are searchable, tagged and modified either from the applications directly or from your own text editor.