The extension will count the modules in your "Content Bottom" module position and layout the modules next to each other in columns. The extension is responsive and will show the module beneath each other in mobile view.

VQMOD install for Opencart 1.5.6.4.
OCMOD install for Opencart 2.x.
VQMOD install for Opencart 3.0.2.0

Included is a text file with extra CSS for column styling. This can be customised as required.

DEMO:
oc1.5.6.4 - https://www.yds.com.au/
oc2.3.0.2 - http://oc23.yds.com.au/index.php
oc3.0.2.0 - https://www.yds.com.au/oc3/