Elegantt for Trello - The most elegant way to manage your Trello projects
TimeSite Pro - TimeSite Pro is a fully configurable, cloud-based time tracking, expense & invoicing solution.
Hello Epics for Trello - Simplify your Trello board with parent/child relationships
TimeSolv - Legal Time Tracking & Billing Software.
TunnelVision - See your next Trello tasks every time you open a browser tab
WiseTime - Web-based automatic time tracking software