You could try AnyDesk for multiple OS functionalities. At the moment, it works on all editions of Windows OS, although there is no version for Mac or Linux. This software is extremely lightweight, taking up only 2 MB of your storage space. Moreover, there are supervision controls for safety, allowing you to see all the actions on the side of the person controlling the PC.

When it comes to security, UltraViewer allows both sides to interact and remove folders they don't want seen in real-time. Transfers happen through a simple drag-and-drop function, although it's advisable to zip files before sending, if there are many of them. Unlike with VNC Connect and other simpler services, you can share and transfer files using UltraViewer, no matter on which side of the connection you are. It allows you to set up hotkeys for activating and deactivating this function, too.

It conveniently comes with a chatbox to facilitate communication between devices. UltraViewer will then show you the other desktop, and you can control it as your own.

Ultraviewer