Markdown by DaringFireball - Text-to-HTML conversion tool/syntax for web writers, by John Gruber
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.
Minimalist Markdown Editor - This is the simplest and slickest Markdown editor.
Boostnote - Boostnote is an open-source note-taking app.
Typora - A minimal Markdown reading & writing app.
Day One - A simple journal application for the Mac, iPhone, and iPad. AboutTo learn more about Day One, see these two excellent reviews . PublishPublish is not available in Day One 2.