Some of those free apps are mentioned here: http://forums.sandisk.com/t5/All-SanDisk-USB-Flash-Drives/Download-new-version-lost-access-to-all-data-Please-Help/m-p/301789#M5953
There are a lot of “free” apps that are only free to download and only free to find lost files then they charge $$$ to actually recover them. Those noted above are totally free.
