Edit: It appears the author of the software has abandoned his website and development of the application. The last version of the utility can still be found on the Internet Archive version of the site.
Checksum is a Windows application that “generates and verifies BLAKE2, SHA1, and MD5 hashes.”
I use it to verify archival data that I have stored on backup hard drives. It is easy to configure, and will quickly generate and/or verify hashes to ensure that the data that was on the drive 6 months ago is the same as the data that is on there now.
It is cheap, fast and does exactly what it sets out to do. It is an essential tool for Windows users who need to ensure the long-term integrity of data.