boxfit(6x) on Linux
The text a758a8991031, as Debian 12 (Bookworm) shipped it.
fills space with a gradient of growing boxes or circles.
Flags it lists
-
--border -
--circles -
--count -
--delay -
--fps -
--grab -
--growby -
--peek -
--random -
--root -
--spacing -
--squares -
--visual -
--window -
--window-id