Fingerprint is an easy to use graphical front end for the command line tool of the same name. Fingerprint is a general purpose data integrity tool that uses cryptographic hashes to detect changes in files and directory trees. Fingerprint generates a snapshot of of a directory and this can later be used to generate a list of files that have been created, deleted or modified. If so much as a single bit in the file data has changed, Fingerprint will detect it.
Available on the Mac App Store.