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.

Flinto - The prototyping tool designers have been waiting for.

Nifty - Manage projects, work, and communications in one place.

Base UI Sketch Framework - Huge set of everything you need to design and prototype

Asana - Asana project management is an effort to re-imagine how we work together, through modern productivity software. Fast and versatile, Asana helps individuals and groups get more done.

Glyphy - Copy & paste fancy fonts + cool symbols ☞✺✐™