The codes fit almost all versions of this operating system for phones and tablets, except the very old ones. IT enthusiasts who have tried them do not, however, guarantee the operation of these codes on all devices, for the simple reason that many times, they ask the phone for a function that was not implemented by the manufacturer or the software developer in the respective model.
The way to enter the codes is very simple, but the effect can be devastating if the user does not know exactly what the effect of activating the hidden function is, so these codes must be tried "at your own risk". Attention! Some codes can reset your phone and you will lose all information and installed applications. Others will give you access to settings that you wouldn't normally want to change.
The codes are entered in the application that forms the phone number, and if it is missing, such as in the case of tablets that do not have a SIM card, it is replaced by the "secret codes revealer" application, which can be freely downloaded from on the internet.
Here is a selection of codes that have been published on several profile sites: