Occasionally I get a little thingy in the top left corner of my Windows desktop. It’s a transparent circular thing that looks like this (magnified in inset):

I recognize the icon but I can’t figure out what it is. It might have something to do with virtual desktops, or I might be misremembering. It goes away when I click on it, or when a window covers it. My suspicion is that I don’t use the program anymore. I couldn’t find anything familiar looking through my Start menu.

Anyone recognize it?

ETA: Aha! It was right under my nose:

It’s FeedDemon’s default icon for a feed that doesn’t have a favicon. When I first saw it I thought it was FeedDemon, but FeedDemon’s own icon doesn’t look like that so I kept looking. Mind you, I still have no idea why it appears at the top of the screen like that, but that certainly narrows down where to look.