I have recently used the ‘photorec’ component of the ‘testdisk’ application for recovering files from FAT32 file systems.
I had used it before to recover files from general USB devices and others like Compact Flash/MMC/Secure Digital media with great success.
Then, I was focusing on recovery of photos and movies.
This time I was looking for various non-image files.
They name may suggest only photos, but this is a great piece of software, regardless of what kind of file you are trying to recover.