Phasmophobia Matrix as SteamVR overlay application.
Based on code from SteamVR-Webkit-Test.
To build you will also need to clone SteamVR-Webkit so that your project structure looks like this:
Projects
├── SteamVR-PhasmoMatix
│ └── SteamVR-PhasmoMatrix.csproj
└── SteamVR-Webkit
├── SteamVR-WebKit
│ └── SteamVR-WebKit.csproj
└── SteamVR-WebKit-Test
└── SteamVR-WebKit-Test.csproj