The 'Last Thanked By You' widget found on the right sidebar of the home page is very useful in making sure you keep up with thanking your direct reports and peers.
Those without Direct Reports will only have the 'Your Peers and Boss' widget. The red plus sign means you haven't thanked that user in awhile. Clicking the plus sign will automatically open up the appreciation tab with that user as the receiver of the appreciation.
A key part of this widget is the part where managers can see the percentage of their direct reports they have thanked this month. As you can see, Leslie has thanked 1 of her 2 direct reports or 50%. This percentage is the same as the data that shows up in the Manager Coverage dashboard in the Insight tab.
For those with many direct reports or peers you will be able to scroll through them as to not clog up the sidebar.