By Joe McGauley

When you use it primarily to snap selfies and crush candy all day, it's easy to forget just how powerful the iPhone in your pocket really is. It's stocked with myriad features you probably didn't even know were there, like the one that's creepily stalking you. Here are six randomly useful functions you should be taking advantage of.

Cole Saladino // Thrillist

1. INVERT YOUR SCREEN'S COLORS TO REDUCE EYE STRAIN.

It's no secret that staring at screens all day, every day is ruining our eyes. To decrease the strain on your peepers, you may want to consider inverting your phone's colors, since it's been shown to make it easier to read at night. To try it out, go into the Accessibility menu under General settings. Once it's enabled, it also inverts the colors your camera sees -- which comes in handy if you're the guy from One Hour Photo and want to look at film negatives.

2. SWITCH UP SIRI'S VOICE.

We're all used to the soothing if robotic canter of that disembodied female voice turning down marriage proposals and cracking jokes, but as they say, change is good. You can give your sassy AI a brand-new identity, making it either male or female with an Australian, American, or British accent. To test-drive the options go to the Siri menu under General settings.

3. CREATE CUSTOMIZED VIBRATION ALERTS.

If the standard "bzzz bzzz" staccato doesn't cut it for you, you can create your very own vibration alert for everything from phone calls to tweets by tapping the screen like a DJ's drum pad. To give it a whirl, tap into the Sounds menu, select the alert you'd like to change, click Vibration, and scroll down to Create New Vibration. And much like you can set distinct ringtones for specific contacts, you can create custom vibrations for them too.

4. PROVIDE LIFE-SAVING INTEL FOR FIRST RESPONDERS. 

Like a digital medical ID bracelet, the latest iPhone iOS versions include the ability to input a variety of important medical info (blood type, medical conditions, allergies, emergency contact, organ donor status, etc.) via the Health app. Any first responder can see all of it by clicking the lock screen's "Emergency" section and tapping the Medical ID button.

Cole Saladino // Thrillist

5. USE IT TO HANG THINGS LIKE AN ADULT.

Eyeballing your wall hangings so they look level is fine if you're still living in a college dorm room, but your big-boy pad requires a little more care and attention. Thankfully, there's a built-in level on your phone. Just open the Compass app and swipe right.

6. SEE WHAT PLANES ARE FLYING OVERHEAD.

Siri's baked-in smarts will give you a digest of all the planes flying above anytime you ask, complete with airline and flight-number details, aircraft type, altitude, angle from your exact position, and even a "sky map."


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