WooCommerce Subscribe All the Things
A few years back I created two add-ons for this plugin. One that provided synchronise options to synchronise the subscriptions billing period and one that allowed you to apply a sign-up fee with an optional free trial for each subscription scheme.
Both of these add-ons were originally developed for clients. At the time WooCommerce Subscribe All the Things was experimental and only a beta.
Now WooCommerce Subscribe All the Things has been re-written and improved making both of these add-ons broken with the current release.
I had plans to update them both but never found the time to put in the work. Now both of these add-on features are currently being worked on to be added as part of WooCommerce Subscribe All the Things so there won’t be maintained any further.