Mac: F.lux, the app that automatically dims your screen at night, has released a beta version that includes OS X Yosemite support. This includes a few new integrations with Yosemite's Dark Mode.
With F.lux, you can now turn on Dark Mode automatically at sunset. It also comes packed with a new Dark Mode icon so it doesn't look too bad up in your menubar. If you're a fan of Yosemite's Dark Mode, the new integration with F.lux is pretty handy.
F.lux beta with Yosemite support (Free) [F.lux]