It is essentially a capture card preview app designed for gaming. You get
- Super Resolution: Uses Apple's MetalFX spatial upscaler, which does about 1K of upscaling. So let's say you output at 4K, the app will upscale the image to 5K. Spatial upscaling is less powerful than temporal upscaling that has access to the GPU, but it also distorts the image less. To me, it is way better to get this small upgrade applied universally to every game than PSSR, a temporal upscaling solution that has so far provided mixed results.
- Super Sampling: I believe this is a custom solution written by the developer, but noticeably improves image quality as well (mainly by reducing aliasing).
- Low-latency: Obviously the one downside of this approach is that the capture card introduces some latency, but the developer claims to have added 0ms of latency on top of the capture card. And you can see the difference when comparing to other capture card preview apps like QuickTime or OBS. Personally I find the latency to be basically unnoticeable for single-player games, and I also play MP games like The Finals using this app no problem. I use the Elgato 4KX.
The recommended settings are Super Resolution: Balanced, Super-Sampling: Medium, Latency: Ultra-low. To me, this turned my PS5 into something I basically ditched for my gaming PC into a great way to play games. I always found PS5 Performance Mode IQ to be lacking, making games look very soft and blurry. But, I also didn't want to play at 30fps. This app makes the Performance Mode on most games feel like an awesome choice. Compared to PC, you are just missing out on fidelity of assets, which doesn't really bother me so much. Of course, you can use this app for Switch or anything else.