When comparing MarkdownPad vs Supernotes, the Slant community recommends Supernotes for most people. In the question“What are the best open source Markdown editors for UNIX-like systems?” Supernotes is ranked 28th while MarkdownPad is ranked 36th. The most important reason people chose Supernotes is:
The note-card format is incredibly versatile, and great when you have lots of information.
Specs
Ranked in these QuestionsQuestion Ranking
Pros
Pro Allows customizing output
A custom CSS can be added to the rendered HTML to change the preview and output.

Pro Real-time HTML Preview
MarkdownPad is split in two panes. One pane is used for writing Markdown, the other shows the rendered HTML as it's written.
Pro Short-form note-cards
The note-card format is incredibly versatile, and great when you have lots of information.
Pro Responsive platform
Works on all devices, from mobiles to laptops.
Pro Full Markdown (with LaTeX equation) support
Great to be able to use all the features of Markdown, rather than a select few.
Cons

Con Many features are disabled in the free version
Free version lacks features like auto-save, PDF export, Markdown tables among many others and can't be used commercially.
Con Abandoned project
Nothing from author since 03/15. Pro version preview pane crashes, no fix has been offered. See user forums.
Con Preview window crashes / does not update
Con Only web apps for now
The developers haven't released native apps yet.
