Gource - Gource is a software version control visualization tool.
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.
Codeology - Open-source algorithm that visualizes GitHub projects
Markdown to PDF - Super simple way to get your markdown files to PDF
The GitHub Matrix Screensaver - Latest commits from GitHub visualized Matrix-style
UnMarkDocs - Unleash the Power of Markdown to Write Better Product Documentation