I am trying to detect when cursor on windows application from Flutter is over certain widget but I cannot find any reference or widgets for this. How can I approach this?
You can use MouseRegion to achieve what you described.
It has two callbacks onEnter and onExit that notifies when the cursor has entered its area and when it has exited.
The area that is going to be tested for entering and exiting is the one you provide in the child attribute.