This app was mentioned in 2 comments, with an average of 9.50 upvotes
Also, need to download another app from Google Play to cast your smartphone screen into anywhereVR screen space: https://play.google.com/store/apps/details?id=jp.co.sme.anywherecastapp&hl=en
If you mean this app:
https://www.youtube.com/watch?v=46q42b-vdHQ
I think it's released only in Japan:
https://play.google.com/store/apps/details?id=jp.co.sme.anywherecastapp&hl=de