I suggest you use MyVision Free.
MyVision Free is a digital classroom management software offered by Netop. This software not only allows you to supervise your student’s computer screens, but also gives you the ability to take control of those screens and lock out their usage remotely.
The user interface for MyVision is clean and simple, with easy to use functionality buttons on its top bar as well as an auto-arrangement feature for screens.
MyVision Free is available for both Mac computers and PCs.
However, I found that Netop did not provide free version of this software now. If you want to use it for free, you can download the old version.
Have a nice day!