When comparing Markdown Edit vs Mark Text, the Slant community recommends Mark Text for most people. In the question“What are the best open source Markdown editors for UNIX-like systems?” Mark Text is ranked 13th while Markdown Edit is ranked 25th.
Specs
Ranked in these QuestionsQuestion Ranking
Pros

Pro Free and open source
Licensed under MIT.
Pro Real-time HTML preview with synchronized scrolling
Markdown Edit is split in two panes. One pane is used for writing Markdown, the other shows the rendered HTML as it's written.
Pro Open Source
Pro WYSIWYG or TEXT visualisation
Pro Has RTL language support
Can be used with languages such as Hebrew and Arabic.
Pro Very light : 103 Mb only
Cons
Con Dead project
Con Covers taskbar when maximised
When maximised, the window covers the taskbar completely even when the taskbar is set to be on top of other windows.
Con Does not support pasting images from the clipboard (unless online)
This editor boasts that it's a desktop (i.e. offline) markdown editor where you can copy and paste images directly in the editor which is a feature that many other markdown editors struggle to implement. Unfortunately this is misleading, since the only way to paste an image in the editor is to be online. If, like many of us out there, you want to work offline, this feature will be broken as it requires an internet connection, which is weird for an editor that boasts being a desktop app!!
Con Not lightweight
On Windows 10 the installed size was 259 Mb, no surprise as this is an Electron based app.
Con Not a WYSIWYG editor, no formated preview
There is only plain text editing.
Con Limited block selections
