Typora - A minimal Markdown reading & writing app.
Jotdown - Slack for social
Dillinger - joemccann has 95 repositories available. Follow their code on GitHub.
Moeditor - The all-purpose markdown editor built with Electron.
StackEdit - Full-featured, open-source Markdown editor based on PageDown, the Markdown library used by Stack Overflow and the other Stack Exchange sites.
Rushline - Anonymously follow people's private conversations