ShellTile

A tiling window extension for GNOME Shell. Just move a window over another one, holding down the Control key, and you'll see the magic! Grouped windows minimize, resize, raise and change workspace together. Maximize a window to remove it from the group.

Example of tiling with multiple windows (holding CTRL)

Example of classic edge resizing (CTRL not needed)

Example of how windows stay grouped

Tutorial video

https://www.youtube.com/watch?v=xX9HUBFj5XE thanks to WOGUE