A fidget spinner for your Mac, as seen on Mastodon and Twitter.
Download from the releases section, unzip, circumvent Gatekeeper or use Sentinel.
It uses a private API, CGSSetWindowTransform, that allows an app to set an arbitrary affine transform on a window. There's also CGSSetWindowWarp that takes a mesh. Here's some more info about these APIs, another example of using them, and Sam's thread that inspired me to build this app.
The dragging of the window is broken when it's rotated.
It works flawlessly on modern-ish macOS, but on 10.x, there are graphical glitches around the window as it rotates. I have no idea what causes this and how to fix it and would welcome a fix or an explanation. Might be related to the shadow.
I set the deployment target to 10.9 (Mavericks) but only tested down to 10.12. It may or may not run on even older versions.
If you get an error mentioning "libarclite" when building a release version using Xcode 14.3 or newer, you need to either raise the deployment target to 10.12 or newer, or install the file Apple removed for some reason.