So bevore trying this extension I'd like to understand where the link, which are approved, are submitted to. Maybe I over-read this part, but its not really clear to me...
Topic on Extension talk:LinkFilter
They are submitted to the link queue, where link administrators (users with the linkadmin user right) can approve or reject them as appropriate. This queue of pending user-submitted links is viewable on the special page Special:LinkApprove. The Special:LinksHome special page lists recently submitted and approved links broken down by category. It's also possible to embed N recently submitted & approved links on a wiki page with the <linkfilter> tag, i.e. <linkfilter count=N /> would display N recently approved links as a list.