If you want to have two identical applications installed on the same terminal, or have root access without spoiling anything, or have a test terminal or just play virtual machines, check out VMOS.
It is an application available on Google Play that allows us to have an android inside our android phone, as if it were a phone inside another, with its own facilities and its independence in almost every way.
VMOS is another and inventive innovation. It virtualizes another local Android working operating system on your own mobile. With VMOS, you can switch among real and virtual OS whenever. The information and applications are put away locally.
VMOS is an Android virtual machine, and we can install it as if it were another normal application. Once installed we can have two accounts of anything, whatsapp, facebook, tripadvisor … it is even possible to have separate space for multimedia, or have separate contacts, for professional and personal use, for example.
One of the main advantages discussed in the description is that you can leave tasks in the background while doing something else, as well as test root access on the new android without having to do it in the main one (the container).
The initial boot takes a few minutes in its first time, and then we can run our android within android taking into account that the performance will not be perfect when the mobile does not have enough memory and processor (more than 32 GB of storage and 3 GB of RAM)
There are several limits, such as the fact that you cannot have your particular SIM, for example, but by virtualizing another native Android operating system on our own phone we can switch between real and virtual systems at any time. During the installation request access to storage, device information, location, IMEI and audio, something necessary for the simulation to be as realistic as possible, so do not be scared by such permission.