Slides - Slides is a place for creating, presenting and sharing presentations. The Slides editor is available right in your browser. Unlike traditional presentation software, like PowerPoint, there's no need to download anything.
Minimalist Markdown Editor - This is the simplest and slickest Markdown editor.
Slidebean - Presentations that design themselves
Typora - A minimal Markdown reading & writing app.
Tome - Tome is a tool for creating stories at work—whether it's about strategy, design, data, or a personal message.
Markdown by DaringFireball - Text-to-HTML conversion tool/syntax for web writers, by John Gruber