draw.io - Online diagramming application
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.
LucidChart - LucidChart is the missing link in online productivity suites. LucidChart allows users to create, collaborate on, and publish attractive flowcharts and other diagrams from a web browser.
Harvest - Simple time tracking, fast online invoicing, and powerful reporting software. Simplify employee timesheets and billing. Get started for free.
PlantUML - PlantUML is an open-source tool that uses simple textual descriptions to draw UML diagrams.
RescueTime - Time management software that shows you how you spend your time & provides tools to help you be more productive.