iSFV is an easy to use integrity checker for SFV files. Use it to test for corrupt files in packages that come with SFV files. You can also use it to edit or create your own SFV files.
TkDC++ is the most simple and lightweight DC client available today. It can be used by the beginner and in a few minutes be downloading from DC. The more advanced user can also use it, as the advanced options can be selected.
Fsum Frontend is a files integrity checker. It can calculate 96 hash and checksum algorithms(CRC32, MD5, SHA1, SHA2, ADLER, DHA256, FORK256, ...). You can verify your files using a .sfv/.md5/.sha1/.sha2 file or create your own checksum file.
Command-line hash file checker/creator. Supports .sfv, .md5, .sha1 and .sha2, and is easily extendable. Includes animated progress bars and recursive directory handling. Supports large numbers of files. Includes AppleScript droplets for use on Mac OS X.