macOS has no public API to rotate another app’s window, and the private call needs System Integrity Protection off — so SpinWin fakes it instead. It hides the real window off-screen where it keeps rendering, captures that window’s buffer with ScreenCaptureKit, and redraws the frames rotated in a transparent overlay sitting exactly where the original was. Ninety-degree steps, arbitrary angles, or a continuous spin, all from the menu bar.