There is no magic. There are two Windows API functions that make goScreen possible: ShowWindow and GetWindowText. So, as long as Microsoft supports this sort of interprocess communication, goScreen will work. When you go from one screen page to another, goScreen just hides all visible windows on the previous page and shows ones on the next.

Hiding and showing a window is a legal operation and all applications should react properly - for example, redraw itself properly. It is one of the major requirements in developing for Microsoft® Windows. Of course, there is no guaranty of how fast they will respond. Here I depend on them - if they are slow, please do not blame me. Also this explains sometimes bizarre behavior of other applications - they might call ShowWindow themselves, or not call it when it would be nice to do so.

GoScreen does not monitor Windows shell activity - this would require installing Windows hooks, which I believe is unsafe. For example, when one double clicks a file in Windows Explorer, shell finds in the registry what application can open this file, starts this application and commands it to open the file. GoScreen is not involved in this scenario.

GoScreen has no initiative. It can do many things, but only when you command it to do so. That is, as long as you do not touch goScreen, it does not touch your system.