Trello - Infinitely flexible. Incredibly easy to use. Great mobile apps. It's free. Trello keeps track of everything, from the big picture to the minute details.

ExpressJS - Sinatra inspired web development framework for node.js -- insanely fast, flexible, and simple

Drag for Gmail - Transform Gmail into organized To Do lists (like Trello)

Chart.js - Easy, object oriented client side graphs for designers and developers.

KanbanMail - A Kanban board for your emails.

Backbone.js - Give your JS App some Backbone with Models, Views, Collections, and Events