How can I keep apps from moving off the home screen? I am using Samsung tablets for workers in the field. They only need to use one app but some users keep moving it off the home screen and then they can't find it.

How can I keep apps on the home screen from moving? Also, I want to keep WiFi turned off because when it is turned on, the device tries to connect to an Optimum hotspot and asks for a user id and password. This is very confusing to non-technical users and I want WiFi to stay off.
A work-around you could use on Android to refrain from having apps move or be uninstalled by either accident or someone trying to purposely do so:

Settings -> Accessibility -> Dexterity and Interaction -> Press and hold delay -> Custom

From here, you can just set an obnoxiously long press and hold delay so that when icons are held down to be either moved or uninstalled, it takes however long you've set the interval for to actually initiate that command. So, a) doing it by accident becomes harder and b) Someone who doesn't know you've set that feature will assume it doesn't work and not opt to wait 35 seconds of holding an icon down.

Just my little trick, at least.