DoubleKiller is a portable app that quickly finds duplicate files and allows you to delete them freeing up hard drive space.This little utility scanned the selected directory fast and then provides you with details like file name, path, size, and CRC32 about all found data. You can utilize it to scan for duplicate files in directories, complete drives, and network PCs. You have the option to exclude files based on specific details like attributes, size, etc., You can set user-defined masks like *.mp3 or *.dll that will allow you to limit the scan to specific files or protect important files from being scanned.The UI for DoubleKiller is very simple and lends itself to easy use even for novice users. Once you the scan has finished it displays a list with all duplicates. From there you can either manually or automatically select the files you want to remove. The results can be sorted and exported easily to a text file.We found that even though this app is not brand new (actually it is a bit old), it worked quite fast and gave prompt results. One thing to keep in mind is, once you decide on a file deletion it does not place the selection in the recycle bin it deletes it straight from the app - so be sure.