How do I clear my notifications?

In the mobile apps, sometimes the notifications will not reset back to zero after you've viewed them. This happens if you've left any notifications without clicking on them, which marks them as "read". To remedy this, either click on each unread notification to clear it, or go to the desktop version, open the notifications link at the top of the page and click the "Mark as Read" link in the bottom right hand corner of the notifications menu. This will reset your notifications count back to zero.