JFBConnect will continue to work just find after your subscription runs out. The only feature that will no longer work is the Autotune service, which requires an active subscription to run.
All features of JFBConnect, such as authentication, social widgets and other features will work when your subscription expires.
Technical support, new releases or use of the auto-configuration tool all require an active subscription.
I hope that helps answer your question.
Thanks,
Alex