Marked gives you options.
Drag to Dock Icon
The easiest way to use Marked on a file you’re already editing is to drag the document icon from the toolbar of your editor or from Finder to the Marked icon in your Dock. Marked will immediately start tracking any Markdown file (or text file) dropped on it. You can also drag files directly from the Finder.
Using the Menu
You can, of course, open Markdown files directly using themenu option. Marked works fine without a text editor, too. You can preview and convert your Markdown with just a click.
From the Clipboard
You can open an instant preview of the contents of your clipboard by copying some Markdown text and selectingor pressing ⌘⇧V. You can have multiple clipboard previews open at once, and you can save them to a new file by choosing (^⌘S).
Creating a New Document
Marked allows you to create a new, empty text file with thecommand (⌘N). It will immediately ask you for a location to save the file, and you can enable the “Edit new files automatically” option in , next to the Text editor button to automatically open the newly-created file in your default editor.
Marked keeps track of recent documents, too. Themenu option will show you the files you’ve had open and let you jump back to them. You can quickly re-open the last file you were viewing with ⌘⇧R. There are a lot of other keyboard shortcuts, too. If you care to learn them, you can find a chart by clicking the Special Features link in the sidebar.