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.
D3.js - D3.js is a JavaScript library for manipulating documents based on data. D3 helps you bring data to life using HTML, SVG, and CSS.
Notion - All-in-one workspace. One tool for your whole team. Write, plan, and get organized.
Chart.js - Easy, object oriented client side graphs for designers and developers.
Slack - A messaging app for teams who see through the Earth!
Google Charts - Interactive charts for browsers and mobile devices.