Switch between normal and split-screen (vr mode)

I have a virtual reality (VR) headset: **How can I change the mode of the phone so that I can use the phone and all the normal phone apps while wearing the VR headset?** In other words I need to switch the phone display between splil-screen (oculus mode) and normal mode. In other words, like for 3D, the display should be split into 2 smaller screens (but identical). ***Related info for those who are interested:*** It seems that there are a few apps available for watching normal videos in VR mode: - Any Youtube video on your device can be switched to VR mode. - Convert normal videos to VR mode by using HMD-Video-Converter. - Play normal videos on the VR headset using: - VR Cinema for Cardboard - CINEVEO - VR Cinema - Side-By-Side Video Player - MO3D for Cardboard VR Cinema (paid)