MarkdownNote 1.1.1 for Mac was available to download from the developer's website when we last checked. We cannot confirm if there is a free download of this app available. The application lies within Productivity Tools, more precisely Office Tools. According to the results of the Google Safe Browsing check, the developer's site is safe. Despite this, we recommend checking the downloaded files with any free antivirus software. This Mac app is a product of Coding Robots.
From the developer:
MarkdownNote makes it really easy to create notes using John Gruber’s popular Markdown markup language in your Mac or iPad. Using live preview feature, you can preview your Markdown markup syntax to HTML on writing. You may sync your documents with Dropbox.com.
You may want to check out more software for Mac, such as pdf-DocPro, Simply Notes or Padre, which might be related to MarkdownNote.