Toby - Better Than Bookmarks
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.
Planyway - Visual project management for Jira and Trello: manage resources, build project roadmaps, use time tracking.
xTab - Limit the maximum number of tabs you can open at once
Corrello - Dashboards for agile teams using Trello