This has a web version[0] which I wish they'd host on a free site.

[0] https://github.com/AlexsJones/llmfit/tree/main/llmfit-web

Edit: I tried to deploy a snapshot of the llmfit-web files on Netlify but it seems to need/want to talk to a backend[1]

[1] https://llmfit.netlify.app/