Note: Since Android P you can not open both cameras simultaneously. There is only Picture in Picture mode, where you can only take pictures, recording is disabled.
This is a Dual Camera app that records and takes picture from front and back cameras at the same time.
This app can be used to record yourself and a really cool band playing at the same time, you can snap a sunset panorama and still be in the picture.
This feature is not supported on ALL android devices, due to the fact that it requires devices to have dual image signal processors, hardware capabilities which most newer devices have.
This app is supported in multiple android devices including Samsung(S8, S8 , Note8), LG, Google Nexus, Google Pixel, Huawei, Xiaomi, LeTV, Elephone etc.
Hope you enjoy !
Samsung disabled the dual mode in Android P.