Flow-e is a visualization layer on top of your Gmail or Outlook inbox. It provides an elegant Kanban-like workflow that's combined with the ideas behind Inbox Zero and GTD. Flow-e eliminates the need of external task management tools and transforms your inbox into a central To Do app.
Twine - Twine is an open-source tool for telling interactive, nonlinear stories.
Sortd - Rated the #1 App for Gmail
Ink by Inkle - ink is a popular open source scripting language for branching stories, designed for writers
KanbanMail - A Kanban board for your emails.
Quest - Quest lets you create sophisticated text-based games, without having to program.
Drag for Gmail - Transform Gmail into organized To Do lists (like Trello)