Give full screen window focus on multiple screens on mouse over

A usability/feature request:

I run a duel monitor set up and 98% of the time I only have two programs open and maximized (firefox and quanta), I code on one screen then switch to the other to test. Some times I forgot which screen has focus and just randomly start typing to fix something.

My proposed solution: If a user has multiple screens and one each screen there is two maximized windows, focus should be given to the window that the mouse is hovering over.

Ideally I'd like something that follows what window I'm looking at, and give focus to it, but that's unrealistic; this is the next best thing I could think of.