There was a problem with the download file for oik v2.5 from oik-plugins.com. This has now been fixed. If you tried to download this version of the plugin recently, please try again. Sorry for any inconvenience caused.
WordPress plugins and themes
Blocks
Shortcodes
Reference
Weight shipping plugins
Find out which cart weight shipping plugin you need for your WooCommerce site.
Which cart weight based plugin do I need?