Pnamur - Pnamur is a smart tool that helps you easily estimate complex projects using a top-down approach.
Gantt - Create beautiful Gantt charts
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.
GoodGantt - The best Gantt chart for Trello®
Chpokify - Planning Poker Tool that saves time of sprint estimation. Agile teams management tools. Jira Integration (Import/Export), auto-summary, smart voting management.
Online Gantt - A free MS Project alternative for simple gantt charts