Flow - Stop managing projects from your inbox.

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.

Planndu - Planndu is a simple task manager app for individuals that helps you to improve productivity and stay focused. It has features to set reminders, status, priorities, and focus techniques to improve concentration and get more of your day.

Planyway - Visual project management for Jira and Trello: manage resources, build project roadmaps, use time tracking.

Fresboard - Notes, tasks & chat - Unified workspaces for projects

Corrello - Dashboards for agile teams using Trello