There are many (always) free alternatives out there which you can find in a fairly comprehensive list at awesome-tunneling [0]. I'd caution anyone as there's always risk with downloading a no sources available binary as well, but this looks like it could be another good option!
My favorite two projects currently in the tunneling space are sish [1] and bore [2]. sish is more full featured and utilizes ssh for handling proxies (disclaimer: I wrote sish) while bore maintains a client/server but all sources are available for both. They're written in Go and Rust respectively. There's even a publicly accessible instance of bore running. You should submit a PR to include CRProxy in the awesome-tunneling list, I know Anders might do that as well as he's normally around these parts :)
[0] https://github.com/anderspitman/awesome-tunneling
[1] https://github.com/antoniomika/sish
[2] https://github.com/ekzhang/bore