Pastebin.com - Pastebin.com is a website where you can store text for a certain period of time.
Markdown by DaringFireball - Text-to-HTML conversion tool/syntax for web writers, by John Gruber
GitHub Gist - Gist is a simple way to share snippets and pastes with others.
Typora - A minimal Markdown reading & writing app.
hastebin - Pad editor for source code.
StackEdit - Full-featured, open-source Markdown editor based on PageDown, the Markdown library used by Stack Overflow and the other Stack Exchange sites.