The application is called Frontback Camera. This application will help you in many things, such as photographing your reaction when photographing a beautiful landscape or someone or any other position. The way to use this application is very simple. After downloading the application from here and opening it you will notice that the software interface is split into two halves At the top is what the rear camera looks like, and at the bottom is what your phone's front camera looks like.
In order to take pictures you can click on the icon in the middle, then you will save the picture as you want, where you can choose to save each image alone or two images next to each other.
