Yes it is compatible with J3.1
See change history
www.jms2win.com/en/faq/change-history-13x
Concerning the extension, see the list of extension defined in the JMS tool menu
www.jms2win.com/en/list-of-extensions?vi...id=269&Itemid=53
When an extension is not defined in the JMS tool menu, this just mean that we never received this extension for a review.
This does not mean that it is not working.
This just mean that you have to either re-install the extension in the slave site or use the Joomla discover menu to install the extension in the slave site.
If you want that we review some extension, please send us the extension in the attachement of an email.