Markdown Preview for (Neo)vim - Preview markdown on your modern browser with synchronized scrolling and flexible configuration.
Previm - Vim plugin for previewing Markdown and Mermaid in browser window.
wool - Preview markdown files in browser or export to html file.
Joplin - Joplin is a free, open source note taking and to-do application, which can handle a large number of notes organised into notebooks. The notes are searchable, tagged and modified either from the applications directly or from your own text editor.
Org mode - Org: an Emacs Mode for Notes, Planning, and Authoring
Typora - A minimal Markdown reading & writing app.