It’s a suspense/thriller where a man spies on a woman in her apartment from a building across the street.  It’s shown from the point of view of the woman’s apartment mostly.  It’s from at least the mid 2000s and it’s not “Buddy Boy(1999)” or “The Resident(2011)”.  Sorry if it’s vague, I honestly can’t remember any more than the spying and that it’s mostly in the woman’s apartment.