The easiest way to do it is to right-click the app's icon on the Dock, then click the "Quit" button. The Santa hat should be gone now. If it isn't, check whether the "Allow automatic icon changes" ...

Nothing says "Happy Holidays!" like Snapping a pic with a festive filter, and there's no place better than Snapchat to bring the holiday cheer to your selfies this time of year. If I'm being honest, I ...