Boardly - A minimalistic planning board for your projects
Paws for Trello - The best way to use Trello on your desktop
Planyway - Visual project management for Jira and Trello: manage resources, build project roadmaps, use time tracking.
Momentum - Agile goal and performance management
Corrello - Dashboards for agile teams using Trello
Hello Epics for Trello - Simplify your Trello board with parent/child relationships