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.
TunnelVision - See your next Trello tasks every time you open a browser tab
Planyway - Visual project management for Jira and Trello: manage resources, build project roadmaps, use time tracking.
Pliim - One click and be ready to go up on stage and present!
Corrello - Dashboards for agile teams using Trello
HiddenMe - Hide desktop icons with a single click.