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.
Weava - Workspace to highlight, organize & collaborate on your research articles.
Roadmap - Collision avoidance for projects and people
Corrello - Dashboards for agile teams using Trello
productboard - Beautiful and powerful product management.