1) JustWifiCam uses NDI-protocol for transfer video by WiFi to desktop. NDI is video industry solution and many apps support it. You can use JustWifiCam with any NDI-compatible software - JustBroadcaster, XSplit, OBS, vMix, Wirecast.
2) NDI allows transfer video with low latency (~200ms) but requires wide bandwidth (~50-100Mbs for good quality). So very recommended use gigabit Wifi (ac/an).
Be aware: NDI developed for quickly and quality transfer video between devices in one local network.
XSplit has good support for NDI (more info). JustWifiCam creates NDI-source so you can add it into XSplit as on picture.
OBS (Windows, macOS, Linux)
You need install NDI-plugin for OBS from here: https://github.com/Palakis/obs-ndi/releases