NotePlan - Make plans inside an individual markdown note for every day in your calendar. Use it as a journal for your daily tasks and plan todos in advance. For Mac, iPhone and iPad.
OctoSearch - Search the repositories starred by your following on GitHub
Markdown to PDF - Super simple way to get your markdown files to PDF
GitHub Visualizer - Enter user/repo and see the project visually
UnMarkDocs - Unleash the Power of Markdown to Write Better Product Documentation
Gource - Gource is a software version control visualization tool.