StackEdit
Open Source
StackEdit is a full-featured, open-source Markdown editor based on PageDown, the Markdown library used by Stack Overflow and the other Stack Exchange sites.
Writebox
Freemium
Writebox is a simple and distraction-free text editor.
Hemingway Editor
Commercial
Hemingway Editor is a proofreading tool for writers.
Compare UberWriter with alternatives
Compare StackEdit and UberWriter and decide which is most suitable for you.
Compare Hemingway Editor and UberWriter and decide which is most suitable for you.
Compare Writebox and UberWriter and decide which is most suitable for you.