I’m shocked I’m saying this, but this app is actually kind of amazing—as long as you keep your expectations in check. I’ve been playing Persona 5 remotely with it (over the internet, not LAN), and it’s been working really well. Now, there are occasional frame rate hiccups and latency issues, and the onscreen controls are only serviceable at best, but that’s totally fine for a slower paced game like Persona. If you expect to play fast paced games remotely where tight controls and fast reaction times are important, you’re going to have a bad time. It might work OK over LAN, but it’s still not going to be great. But for certain slower games, it works nearly perfectly.
A few details about my setup: I was not able to get the automatic remote setup working with my router configuration. I had to look at R-Play’s help docs for opening the right router ports to get everything working, but if you’re reasonably capable at futzing with router settings, you shouldn’t have any issues. My PS4 is connected to my router with an ethernet cable, and my home internet speeds are 60Mbps down and 6Mbps up.