Just tried it, pretty slow (6.4 MB/s) maybe due to encryption (as mentioned in the github repo) but anyway it doesn’t utilize WiFi direct, works almost the same as every other app out there (both devices must be connected to the same network)
Just checked the github repo and I’m honestly disappointed seems like the devs ain’t interested in supporting WiFi Direct, they can’t see what sets it apart, well you know what they say if you want something then do it yourself