The linked "Introducing Stashpad" blog post doesn't show or tell what this is. Instead visit the Stashpad homepage [1] or watch their two-minute "Stashpad Quick Start Guide" video [2].
I learned that Stashpad is a hierarchical notepad with an attractive interface and an emphasis on keyboard shortcuts. The notes support Markdown. The application can be downloaded after submitting an email address. Stashpad runs on Mac, Windows, and Linux.