Inkdrop is a Markdown-flavored notes editor that also syncs your data to the cloud to you can access the entries on all your devices.
Note: price is that based off of a monthly charge.
Updated on Aug 22 2017
Note: The demo version is currently at 3.7.3; the version available for purchase is 3.8.0.
Note: Now requires OS X 10.11.4 or later.