SpinWin

A macOS menubar utility that visually rotates a selected window by any angle (90° increments, arbitrary angles, or a continuous spin).

How it works (and why)

macOS has no public API to rotate another app's window. Real rotation would require private SkyLight calls (CGSSetWindowTransform) with System Integrity Protection disabled — not worth it.

Instead, SpinWin fakes it:

• Hide the selected window off-screen via the Accessibility API. It keeps rendering there, so it can still be captured.
• Capture its contents continuously with ScreenCaptureKit (SCStream + desktopIndependentWindow filter) — this grabs only that window's buffer, so the overlay never mirrors itself.
• Draw the frames in a transparent, borderless overlay window placed where the original was, rotated with a CALayer transform.

Because it's a layer transform, any angle works — the overlay is sized to the rotated content's bounding box so nothing clips, and a diagonal-sized square is used while spinning.