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.

SlimPlanner - Team scheduling, resource planning, task management

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

Corrello - Dashboards for agile teams using Trello

WorkPatterns - The modern manager's toolkit: 1:1s, feedback, & recognition

Wiplo - The easiest way to organize and run your business workflows.