All news
productdevtools

SpinWin: macOS App That Rotates Any Window

28 Jul 2026

SpinWin is a new macOS menu bar utility that does something no window manager typically offers: it visually rotates any selected window by any angle. Announced via Show HN, the tool supports 90° increments, arbitrary angle rotation, and a continuous spin mode.

How It Works

SpinWin's approach is a clever workaround rather than a native OS feature. According to the report, the app:

  • Uses the Accessibility API to move the selected window off-screen, hiding it from view.
  • Continuously captures that hidden window's contents using ScreenCaptureKit, specifically via SCStream and a desktopIndependentWindow filter.
  • Renders the captured frames into a transparent, borderless overlay window, applying rotation through a CALayer transform.

The result is a live, rotated "picture" of the window displayed on top of the desktop. Releases are signed with a Developer ID and notarized by Apple, pointing toward distribution outside the Mac App Store.

Permissions Required

Because of its technical approach, SpinWin requires two sensitive macOS permissions:

  • Screen Recording — to capture the window's contents via ScreenCaptureKit.
  • Accessibility — to move the source window off-screen and restore it later.

The Catch: It's Not Interactive

The rotated overlay is a live picture, not a functional window. Per the report, clicks and keystrokes are not sent through to the real window underneath — meaning users can watch a window spin, but can't actually work inside it while rotated.

Other limitations noted in the report include:

  • Mission Control and Exposé can leak the hidden, off-screen window, which appears unrotated in those views.
  • Some apps throttle rendering for off-screen windows, which can slow SpinWin's capture feed.
  • If a window resizes itself while rotated, it retains its original footprint until rotation stops.

No pricing, licensing, macOS version requirements, performance benchmarks, or multi-monitor behavior were detailed in available information.

Why Founders Should Care

SpinWin is a niche utility, but its build approach offers a window into broader macOS devtools opportunities:

  • System APIs as a foundation: The combination of ScreenCaptureKit and Accessibility APIs likely signals room for other creative window-manipulation tools — founders building for macOS may find similar API combinations underexplored.
  • Permission friction is a real cost: Tools requiring both Screen Recording and Accessibility permissions will almost certainly face user trust and onboarding friction, given how sensitive these prompts are perceived to be. Founders should plan onboarding flows accordingly.
  • Distribution signals: Developer ID signing and notarization — rather than App Store sandboxing — may suggest this class of tool is better suited to direct distribution, a consideration for founders weighing sandboxed vs. open distribution tradeoffs.
  • Technical ceiling is real: The non-interactivity limitation suggests that fully seamless window manipulation (rotation with live interaction) remains a hard, possibly unsolved problem on macOS — a potential opportunity for a more ambitious technical solution, though likely with meaningfully higher engineering cost.

What's Missing

The report leaves several open questions: there's no confirmed pricing model, no compatibility details across macOS versions, no performance benchmarks (frame rate, CPU/GPU load), no adoption or download data, and no clarity on multi-monitor support. Founders evaluating similar tools — or considering building competitors — should treat these as open due-diligence items rather than assumptions.

Sources