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.

Workona - A better way to work in the browser.

Roadmap - Collision avoidance for projects and people

OneTab - Whenever you find yourself with too many tabs, click the OneTab icon to convert all of your tabs into a list. When you need to access the tabs again, you can either restore them individually or all at once.

productboard - Beautiful and powerful product management.

Session Buddy - Manage Your Browser Sessions