WiseTime - Web-based automatic time tracking software
Ollert - Learn what your Trello boards aren't telling you
TimeSite Pro - TimeSite Pro is a fully configurable, cloud-based time tracking, expense & invoicing solution.
OutlookTime - OutlookTime is a time tracking system that turns Outlook into a timesheet system.
SendBoard for Trello - Receive and reply to emails in Trello
TimeSolv - Legal Time Tracking & Billing Software.