Use your phone's camera as a wireless webcam in your PC or Mac.
Install Webcam for Windows, Mac or Linux, download Iriun Webcam app to your mobile phone and start using the phone with your favourite video applications.

Use your phone as a Virtual Reality display. Iriun VR makes it possible to play SteamVR games with low cost headsets. Install needed drivers and start playing your favourite SteamVR games.