PaperWM is described as 'experimental Gnome Shell extension providing scrollable tiling of windows and per monitor workspaces. It's inspired by paper notebooks and tiling window managers. Supports Gnome Shell 3.28 and 3.30 on X11 and wayland' and is an app in the OS & Utilities category. There are more than 25 alternatives to PaperWM for a variety of platforms, including Linux, BSD, Mac, Windows and FreeBSD. The best alternative is i3, which is both free and Open Source. Other great apps like PaperWM are Openbox (Free, Open Source), awesome (Free, Open Source), Xmonad (Free, Open Source) and Sway (Free, Open Source).