Todoist - Todoist is a to-do list that helps you get organized, at work and in life.
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.
doo - A smart, simple app for reminders and to-dos
Hours - Boosting productivity through live, virtual co-working.
Laverna - Laverna is a JavaScript note taking application with Markdown editor and encryption support.
Futuramo Time Tracker - Futuramo Time Tracker is a time tracking solutions designed for freelancers and teams.