I made a Swift library, Logician (https://github.com/mdiep/Logician), based on microKanren with the help of these links. I also wrote about how it works with Swift: https://matt.diephouse.com/2016/12/logic-programming-in-swif...

I haven't had the chance to build anything that uses them. But having become familiar, I think there are lots of potential applications. I always thought that Prolog was strange. Logic programming makes a lot more sense as a library IMO.