Pennywise enables multitasking by letting you keep any app window open and on top of all other windows on your computer.
Way Cooler is a tiling window manager to help you manage windows on your Linux machine.
Veeer is a window manager that maximizes your workflow speed with its features on your Mac.
If you want to manage your windows more efficiently, Amethyst can help you do that with its features.
If multitasking is part of your daily work, Window Collage will help you organize your work windows the way you want.
FastWindowSwitcher allows you to quickly switch between windows on your computer.
If you don’t find the default behavior of moving and resizing windows to be good in Windows, then give AltDrag a try as it wholly changes how you manage software windows on your computer.
Spectacle is a free and open source Window Manager software for Macs.