Taskful - Deadlines, meet your match.
Toggl - Toggl is an online time tracking tool. It features 1-click time tracking and helps you see where your time goes. Free and paid versions are available.
Calendarist - Time blocking companion for Google Calendar
Hours - Boosting productivity through live, virtual co-working.
Gone - An ephemeral to-do list
Futuramo Time Tracker - Futuramo Time Tracker is a time tracking solutions designed for freelancers and teams.