Markdown-Supported Tool

Productivity App:

• Notion: all-in-one knowledge management tools
• Obsidian: Markdown note-taking app
• Trello: kanban project management
• Joplin: note-taking app
• Logseq: note-taking app
• Typora: essay and report document editor
• Simplenote: note-taking app

Social:

• Reddit: dicussion forum
• Slack: team messaging and collaboration app

Markdown Editor:

• Stackedit: in-browser live view markdown editor
• marktext: open-source markdown editor
• VS Code: all-inone code editor
• Google Docs: docx to markdown converter

Majority of tools and platform support markdown. The lists is the application and platform that you might be familiar with.