There are a few footnote/endnote plug-ins available. In my opinion, some are overly complex for what the task requires.
This one is simple and to the point. Does the job well.

I would suggest it needs to allow the user to specify the short-code. Currently it is set to [footnotes][/footnotes]. This is especially important for users switching from another footnotes plugin, which may use a different short-code or allows for a user specified short-code (and the user selected something other than “footnotes”). In my case, I have a great many existing footnotes notated with [ref][/ref].

Thanks to the developer for his great work on this plugin.