Microsoft PowerToys’ Crop and Lock lets you make mini app windows

This is really neat for little windows where you want to monitor something (like Steam downloads, as in the post) versus opening up the entire window.

PowerToys has been solid, I still haven't found the equivalent to FancyZones in either Linux or macOS. Some are similar but I want to keep the layout static rather than being dynamically resized like in usual tiling window managers.