I had need of decrypting Rijndael encrypted strings, monkeying about with the decrypted info, then encrypting the monkeyed with info. I'd struggled with a couple of other options before hitting CryptX. In about 5 minutes, I was on my way. The documentation and examples were clear enough for me to follow with little trouble.
A while ago I added this as a dependency in NicTool. The interface is a little different but it works quite well. Being able to replace multiple crypto modules (SHA* and MD5 for legacy and PBKFD2 for present) is a lovely feature.