Whether or not you give a hoot about the new 4in iPhone or cheaper Apple Watch, if you have an iPhone you should be pumped about the latest version of iOS 9 that just rolled out with them. It's packed with lots of tiny tweaks and new features for iPhones and iPads, but the coolest addition is something Apple's calling Night Shift mode. It's a game-changer for low-light situations, and it will even help you sleep better.
It's no secret that the iPhone's glowing screen can mess with your eyes and throw off your circadian rhythms, resulting in a screwy sleep schedule. Enter Night Shift mode, which is basically a baked-in version of the f.lux iPhone app. It gradually and automatically changes the color temperature of your phone display based on the time of day, thus reducing the amount of blue light emitted from the screen for happier eyes and better sleep.
To set it up, first you have to update to iOS 9.3. Then go to Settings > Display and Brightness > Night Shift and select what time you want it to turn on. You can create a custom schedule, or set it to run from sunset to sunrise -- which it automatically detects based on whatever time zone you're in. And if you suddenly find yourself in some romantic mood lighting and want to enable it on demand, there's an easy shortcut via the Control Center: swipe up from the bottom of the screen and tap the sun/moon icon.
You may notice that Night Shift doesn't work while you're in Low Power Mode -- and that's by design, since it does eat up a decent amount of battery energy. However, the smartypants at 9to5Mac discovered a neato workaround that involves asking Siri to help you out so you can use both features at once.