I want to create App that Make My Device with multi-Users “username and password for every user”
Users can share the Device , every user can open different Apps “Ex. Camera , Contacts” and prevent from another app
the App must run at system Start up request your username and password and then
the App will Make You Run Some App and Prevent you from some App
Clearly this isn’t possible with the stock Android ROMS – security like that has to be implemented by the operating system and no app has that level of control.
Also, if you don’t know that this isn’t possible, you are unlikely to have the knowledge to implement the other things an operating system has to do like memory/disk management, security, etc…
If you really want to try, you need to get hold of an Android ROM and start modifying it. This will require low-level understanding of the hardware, processor, etc… and would require rooting the target device