Better Notes - Simple notes app that ties notes together with #hashtags

Ziteboard - Ziteboard is an zoomable online whiteboard that lets team to collaborate in real-time.

Paper - Super-clean writing space with a lot of configurability that stays out of sight when you don’t need it.

Voynetch - Share your visual notes and graphic recordings.

Evernote - Bring your life's work together in one digital workspace. Evernote is the place to collect inspirational ideas, write meaningful words, and move your important projects forward.

AuthorBee - Organize Twitter around your interests