Just on a quick note: Android have a ‘multiple’ User features. The idea is simple and like in Windows. Different Users can share the same device. However, this feature is broken. The initial creation of a new User renders the phone useless till a reboot. Followed by a odd reboot cycle of several times. It took some time till switching was working and does each time have a slow down.
You can not just ‘simply’ share files or apps.  It is possible to share files by using a special folder
/sdcard/Android/obb to make it accessible to others.
The Unix permission system underneath is completely not usable or of any sense here. There are not groups whatsoever and the new User might able to install Apps
on his own, but only when these are not presented by the other user. Sharing App data seems to be not possible, at least not without any App. It might be
possible to have user share the same Google Play Account. It does not tell how apps can be shared. Besides, there seems to be quite a lack on documentation
to this regards. In the end the App might need to support this. It feels like that even Windows 95 had got this better..
so far akendo