To sync or use the VR headsets with your iPhone 12 or pro max, you might not need any specific app. However, it could also depend on the VR headsets that you opt for. Most of the VR headsets on the list are ready to go with easy plug and play. Similarly, the app, game, or website you plan to use a VR headset should have VR-support. Most of the latest apps come with VR support. You can access it separately from the menu, like in YouTube and other streaming apps.