SongKong also provides manual editing and this is fully functional with free Melco Lite license.
This allows direct editing of music files on your Melco without having to copy the files
to a desktop computer to be modified by a conventional music tagger and then copied back.
Spreadsheet UI
Manual Editing uses a spreadsheet like UI. This gives the quickest way of editing multiple fields and files.
Google Image search
Comes with a handy Google Image search for looking for missing artwork