Rename many files at once. Great to use in your SendTo profile folder. This was only meant as a small utility I can use myself to prepend and append strings to my file names with the option to change all their extension.
What's the purpose? For example, if you have two or three songs in each music album subfolder, you may be better off organizing your files to include the album name in front of the track name within the file's name so you can put all those files in one folder but still know which album they came from.