Like a lot of people, I use a MacBook Pro as my main computer. The 15-inch screen hits a sweet spot in terms of size and functionality. It’s big enough to be useful on the go, but not so big that carrying it around becomes a burden. But when I’m at my desk, I need the extra space a Cinema Display provides. It’s a great setup, but because of the different screen sizes, I’m constantly juggling windows around as I switch between my external monitor and my MacBook Pro’s display. Stay is a simple but powerful utility that solves that problem--and even if your setup only includes a single display, Stay’s window-wrangling powers are impressive.