f.lux
f.lux is the original pioneer of circadian-aware screen filtering. It automatically adjusts your screen's color temperature based on your local sunrise and sunset, reducing blue light exposure as you approach bedtime.
Ingredients & Purity
Lightweight software that adjusts the color gamut of the display. It uses your location to sync with the solar cycle.
Scientific Evidence
f.lux has been cited and used in numerous academic studies regarding screen light and sleep quality.
Brand Transparency
While not open-source, the creators provide a wealth of research links and spectral maps on their website to explain the 'why' behind their presets.
Value Assessment
Unbeatable value as the software is free for personal use while providing professional-level circadian regulation.
Why Not Alternatives?
It is completely free and has been the gold standard for over a decade. While it lacks the PWM controls of Iris, its ease of use and 'set it and forget it' nature make it the best entry point for circadian health.