gTile is a gnome-shell extension that tiles your windows as you like within grids of 2×2, 3×2, 4×4, 6×6, and others as your configure extension.js.
GNOME 3.2+ using Firefox web browser to get gTile from
Or, use git:
git clone https://github.com/vibou/vibou.gTile
Move it to “~/.local/share/gnome-shell/extensions” and enable via Gnome Tweak Tool.
To configure gTile open the file “extension.js” under “~/.local/share/gnome-shell/extensions/gTile@vibou/”, go down to SETTINGS comments and edit the part of code.