A calm menu-bar / tray app for macOS and Windows that keeps your screen in sync with the sun: warm circadian color (6500 K days, 2300 K nights), night-scaled dimming, and flicker-free (PWM-safe) dimming with battery awareness.
macOS install (Circa.zip): unzip, move Circa.app to Applications, right-click → Open on first launch (ad-hoc signed). macOS 14+, Apple silicon.
Windows install (Circa-windows-x64.zip): unzip, run Circa.exe. SmartScreen asks once: More info → Run anyway. Windows 10/11 x64. The panel opens on first launch and the ring icon lives in the system tray.